Investment Casting

This study aimed to determine the effect of using acrylonitrile butadiene styrene in place of conventional wax material on treatment pattern removal in the investment casting process. There are three controllable process variables that can affect treatment pattern removal, which include temperature increase, holding time and the number of layers of ceramic shell that have been considered for comparison. Comparison among the effects of temperature increase, holding time and numbers of ceramic shell layers on the ceramic shell was analyzed using ANOVA. It was found that temperature increase (Tx), holding time (t) and number of layers of ceramic shell (N) contribute significantly to the length of the crack (l) on the ceramic shell. The crack in the ceramic shell's surface was analyzed using scanning electron microscope photos. Less layers number cause the increase of crack length. The combination between temperature upraise and longer holding time cause cracking delay. The experimental is conducted by using 3 (three) variants for each of layers number, temperature and holding time. The layers number is ranging between 7-9 layers. Temperature increase from room temperature until 1300 o C. The layers number variant is ranging between 180-300 seconds. It was concluded that a longer holding time will result in a more intact ceramic shell, as longer holding times yield short crack lengths.

The ceramic shells were fabricated with ceramic slurry containing zirconia as filler material and colloidal silica binder to cast Zr-alloy 705. The investment shell mould characteristics in terms of hot bending strength, thermal expansion and metal-mould reaction were measured. On account of phase transformation (confirmed by Raman spectra) of zirconia at high temperatures the hot bending strength zirconia shells decreases with increasing temperature. A hard ZrO2 case layer was noticed beneath the surface of the casting.

Foam metals have always been an interesting material type because of
their unique properties and various production techniques. In this
study, solid mold investment casting process, which is one of the replication
techniques, was used to produce open-cell aluminum foam specimens.
Commercial rubber sponge was tested as foam pattern material.
Plaster bonded solid molds were prepared in the stainless steel flasks
and infiltration of the slurry into the rubber sponge was carried out
under vacuum. Following this, pattern removal and mold firing was
carried out gradually. Molten A319 casting and A6063 wrought aluminum
alloys were cast into flash molds with vacuum assistance (-105 Pa).
Sponge pattern and cast foam specimens were examined and compared
by stereo microscope and scanning electron microscope (SEM). It is
clearly found that rubber sponge is a very suitable pattern material for
producing open-cell foam structures.

This paper highlights the usage of colloidal silica (commercially known as SILOX) as a binder for the investment casting process. This binder provides more strength to the investment shells and it is environmentally friendly. It can be easily mixed with refractory powders or grains to give brushable and sprayable slurries. The filler material used to prepare the investment slurry was zircon powder. It has the advantage of high refractoriness, low thermal expansion, resistance to wetting by molten metal and a fine particle shape. The stuccoing of the investment shells was made by using high refractory sand with AFS grain fineness number of 120 & 35 respectively for primary and secondary coats. The investment shells made with these materials were tested for bending strength and permeability. The effect of slurry viscosity, air drying time between coats and addition of electrolyte (ammonium acetate) on the properties of bending strength and permeability was also studied. The results of the investigation indicate that the addition of electrolyte (ammonium acetate) increase the viscosity of the slurry thus increasing the bending strength. The bending strength of the shells found increased with the increase in the viscosity of the slurry and also with the air drying time between the coats. The permeability of the shells decreased with the increase in the air drying time.

The development of hip joint materials has improved rapidly in the fields of biomedical sciences. This is also accompanied by the advancement of the investment Mechanical Properties of AISI 316L for Artificial Hip Joint Materials Made by Investment Casting http://www.iaeme.com/IJARET/index.asp 176 [email protected] casting process for making artificial hip joint materials. Recently, the use of steel alloys as biomaterials has grown. 316L stainless steel hip joint made using investment casting with duraluminum (Al-Cu alloy) molding was examined in the study. The purpose of this research was to evaluate the mechanical properties of AISI 316L material after the investment casting process. The mechanical characterization included tensile test, hardness test, and impact test. The results of mechanical property testing were compared to those of 316L stainless steel Ultra-Vision products and ISO 5832/1. Yield strength, ultimate tensile strength, elongation (%), hardness (HV) and impact strength for the investment casting product are 375 MPa, 579 MPa, 28 %, 126 HV and 95.06 J, respectively. In this study, the percent elongation for the investment casting product did not meet the minimum the percent elongation requirement specified by ISO 5832/1, but the hardness and strength of the investment casting product are greater than those of ISO 5832/1 standard. This investment casting approach may be adopted for making AISI 316L hip joint with the improved mechanical property.

With CAD/CAM technology moving from myth to mainstream applications, most industries are caught between change and survival. This is especially true in the case of small and medium industries. This paper attempts to answer the question: "Is CAD/CAM necessary and economically justifiable for small and medium industries?" by focusing on four aspects: key developments, benefits, bottlenecks and strategies.

With a glance on the Corrosion Rate (CR) formula: í µí° ¶í µí±… = 534 × Δí µí±¤ í µí°´× í µí°· × í µí±¡ [í µí±ší µí±í µí±¦] µm y^-1 = µm/y= micrometer per year [all are the same] Our goal is to have the same formula but in the µm í µí±¦ −1 or micrometer per year As we all know that every inch equals to 0.0254 meter which clears our way for transforming mpy to µm/y: 1 í µí±–í µí±›í µí±ℎ = 0.0254 í µí±ší µí±’í µí±¡í µí±’í µí±Ÿ With a simple multiplication mpy would transform to µm í µí±¦ −1 as following: 1 í µí±–í µí±›í µí±ℎ 1 í µí±¦í µí±’í µí±Ží µí±Ÿ × 0.0254 í µí±ší µí±’í µí±¡í µí±’í µí±Ÿ 1 í µí±–í µí±›í µí±ℎ = 1 í µí±ší µí±–í µí±í µí±Ÿí µí±œ í µí±ší µí±’í µí±¡í µí±’í µí±Ÿ 1 í µí±¦í µí±’í µí±Ží µí±Ÿ × 10 3 Now the standardized dimensions: 1 [í µí±–í µí±›] 1 [í µí±¦] × 0.0254 [í µí±š] 1 [í µí±–í µí±›] = 1 [µí µí±š] 1 [í µí±¦] Which would result: í µí° ¶í µí±… = 534 × 0.0254 × Δí µí±¤ í µí°´× í µí°· × í µí±¡ [í µí±ší µí±í µí±¦] = 13.5636 × Δí µí±¤ í µí°´× í µí°· × í µí±¡ × 10 3 [µí µí±š í µí±¦ −1 ] Q.#2: Converting mpy to mdd in CR Formula: We are going to convert mpy to milligram cm^-2 day^-1: Let's write down the relations:

Blade/vane components used in aerospace turbines are of twisted aerofoil shape, made by the process of investment casting, using Ni based super-alloy materials. These castings operate at turbine inlet temperatures (TET) close to the melting point of the alloy, in order to maximize thermal efficiency and thrust of the engine. The castings are made hollow, with intricate features such as turbulator, pin-fin, etc built-in to maximize the effect of heat transfer during forced cooling through internal passages. The hollow geometry in the castings is produced during the investment casting process by using a suitable ceramic core made from Silica or Alumina based mixes. These ceramic cores are high pressure injected by forcing the ceramic mix into dedicated molds or dies. Development of such dies is an involved process by itself, addressing issues right from ceramic mix behavior to manufacturability of the injection mould. The present paper attempts to highlight issues related to tooling development for ceramic cores used in investment cast turbine blade/vane components.

Investment casting is one of the oldest manufacturing processes, dating back thousands of years, in which molten metal is poured into an expendable ceramic mold. The mold is formed by using a wax pattern-a disposable piece in the shape of the desired part. The pattern is surrounded, or "invested", into ceramic slurry that hardens into the mold. Investment casting is often referred to as "lost-wax casting" because the wax pattern is melted out of the mold after it has been formed. Investment casting requires the use of a metal die, wax, ceramic slurry, furnace, molten metal, and any machines needed for sand-blasting, cutting, or grinding. In the present study, an attempt has been made to produce a wax blend which could offer minimum linear and volumetric shrinkage and better surface finish. Experiments were conducted with different types of waxes namely Paraffin wax, Bees wax, Carnabua wax and Microcrystalline wax by varying their proportions. In each case, properties of wax pattern like surface finish, percentage linear and volumetric shrinkage were determined. An attempt was made to find out the set of input parameters, which could offer a set of ideal properties ofthe wax blend, using Taguchi method. The set of input parameters suggested by Taguchi method was experimentally verified and found to offer the set of desired optimal properties of the wax blend pattern.

Im Frühjahr 1969 wurde bei Ausgrabungen der Universität Bonn unter Leitung von Elmar Edel auf der Qubbet el-Hawa ein außergewöhnliches Depot mit Materialien einer antiken Gusswerkstatt gefunden. Im Zuge der Fundteilung gelangten die meisten Stücke des Konvolutes in das Ägyptische Museum der Universität Bonn und werden dort aufbewahrt.

Die Deponierung des für die Forschung zur antiken Metallurgie bisher einzigartigen Konvoluts geschah im Zuge der Nachnutzung von Grabanlagen aus dem Alten Reich (um 2100 v. u. Z.) in der ägyptischen Spätzeit (um 550 – 400 v. u. Z.). Das Depot enthält Objekte, die alle Fertigungsstufen von Metallgegenständen im Wachsausschmelzverfahren dokumentieren. Es wurden Stücke von Rohwachs sowie Wachsmodelle und die zu deren Herstellung genutzten Negativformen gefunden. Weiterhin enthielt es vollständige Gussformen, die in einem aufwendigen Mehrschalenverfahren hergestellt wurden und teilweise bereits für den Guss ausgebrannt worden sind. Schließlich zählen einige Metallfiguren sowie weitere figürliche Objekte zum Konvolut, die alle in den Bereich einer kunsthandwerklichen Werkstatt deuten. Eine Besonderheit stellen zudem Gussformen dar, in denen Fragmente von Metallfiguren zur Reparatur im Überfangguss vorbereitet waren.

Das Depot wurde in der Gesamtpublikation der Bonner Grabungen bisher nur summarisch vorgestellt. 2014/15 initiierten die Abteilung Ägyptologie der Universität Bonn und das LVR-LandesMuseum Bonn unter Ludwig D. Morenz und Michael Schmauder ein gemeinsames und von der Fritz-Thyssen-Stiftung gefördertes Forschungsprojekt, das von Martin Fitzenreiter, Johannes Auenmüller und Frank Willer geleitet wurde. In Kooperation mit Dietmar Meinel (Bundesanstalt für Materialforschung und -prüfung Berlin / BAM, Fachbereich 8.5 Mikro-ZfP), Roland Schwab (Curt-Engelhorn-Zentrum Archäometrie gGmbH, Mannheim), Gerwulf Schneider (FU Berlin, Exzellenzcluster TOPOI), Ursula Baumer und Patrick Dietemann (beide Doerner-Institut / München), Thorsten Geisler-Wierwille (Steinmann Institut für Geologie, Mineralogie und Paläontologie der Universität Bonn) sowie Ursula Tegtmeier (Labor für Archäobotanik der Universität Köln) wurden die Objekte des Konvolutes eingehend und mit zeitgemäßen Verfahren untersucht. Die Ergebnisse dieses Forschungsprojekts werden in dieser Publikation vorgelegt.

The ceramic shells were fabricated with ceramic slurry containing alpaha and gamma alumina as filler materials and colloidal silica binder. The shell characteristics in terms of bending strength and thermal expansion were measured. The phase transformation from gamma to alpha alumina were observed with transmission electron microscopy (TEM) and selected area electron diffraction (SAED) patterns.  The metal to mould reaction were revealed with optical microstructures and hardness distribution. The bonding mechanism in the alumina and colloidal silica binder system was due to formation siloxane bonds. The phase transition γ- → α-Al2O3 occurs in two phases, respectively in the temperature ranges of 600°C - 850°C cubic crystal structure and from 850°C - 1000°C, α-Al2O3 with corundum crystal structure. The cracks have been observed in the investment shells made of gamma alumina after 7075 Al-alloy pouring.

Modern turbine engines for aerospace applications need precision investment cast components such as integrally cast rotors and
stators, for their hot end turbine stages. Traditionally, these turbines are used as starter engines. In recent times, such engines are
also used for strategic missile applications. The rotor/stator castings consist of a central hub (shrouded in some designs) over
which a number of aerofoil shaped blades are located. Since these components cannot be machined, investment casting is the
only available route for manufacture and hence stringent dimensional aerospace quality has to be in-built in the casting process
itself. In the process of investment casting, pattern generation by injection of wax into dedicated dies/moulds is the first critical
step. Traditional approach deals in producing individual blades with hub/shroud features through wax injection and assembly of
a set of such injected patterns onto a dedicated and precisely manufactured fixture to wax-weld and generate an integral wax
pattern, a process known as the ‘segmental approach’. It is possible to design a single-injection die with retractable metallic
inserts in the case of untwisted blades of stator patterns without the shroud. Such an approach is also possible for twisted blades
of rotors with highly complex design of inter-blade inserts and retraction mechanisms. DMRL has for long established methods
and procedures for the above to successfully supply precision castings for various defence related projects. In recent times, urea
based soluble insert approach has also been successfully applied to overcome the need to design and manufacture a precision
assembly fixture, leading to substantial reduction in component development times. Present paper deals in length various
approaches tried and established at DMRL to generate precision wax patterns for aerospace quality turbine rotors and stators. In
addition to this, the importance of simulation in solving issues related to wax injection is also touched upon.

Medical applications are some of the most interesting applications of the rapid manufacturing using rapid prototyping (RP) technologies. The technology is able to produce a physical model of the organ structure, which is very useful for diagnosis, surgery planning, training, and for design and manufacture of the custom implants. The paper presents the rapid manufacturing process i.e. casting using RP pattern & material used for casting is SS316L. In this study investment casting process is used for development of customized femur implant. For the defect free casting, the simulation programs (AutoCAST-X) are used to achieve sound, high quality castings. This paper seeks to review the industrial applications of state of the art additive manufacturing (AM) techniques in metal casting technology. The procedure for design of casting system for any intricate shapes has been elaborated, thus foundry engineer facing difficulty. RP pattern based investment casting overcomes the conventional wax pattern process along with validated & optimized process. With the use of computer software the mold filling and solidification has assured the quality of castings with a higher degree of confidence, and reduces the cost of rejects. The effective use of simulation software has resulted in major improvements being realized in the areas of controlling shrinkage porosity defects.

In this study, expanded polystyrene (EPS) was used as a pattern material in investment casting and removed chemically by acetone. It
is shown that EPS is an alternative pattern material to the wax material which is used in the conventional investment moulding. EPS pattern
usage and chemical removing change basically the investment moulding process. The ceramic shell moulds with wax and EPS patterns
were produced at the same dimensions and with the same techniques. Unmodi ed A 413 Al-Si alloy was cast into these moulds. XRD and
SEM characterizations were performed on the mould internal surfaces, and image, EDS and surface roughness analysis were carried out
on the cast parts for comparison. The effects of chemical removing of patterns on the structure of mould internal surfaces were investigated.

Medical applications are some of the most interesting applications of the rapid manufacturing using rapid prototyping (RP) technologies. The technology is able to produce a physical model of the organ structure, which is very useful for diagnosis, surgery planning, training, and for design and manufacture of the custom implants. The paper presents the rapid manufacturing process i.e. casting using RP pattern & material used for casting is SS316L. In this study investment casting process is used for development of customized femur implant. For the defect free casting, the simulation programs (AutoCAST-X) are used to achieve sound, high quality castings. This paper seeks to review the industrial applications of state of the art additive manufacturing (AM) techniques in metal casting technology. The procedure for design of casting system for any intricate shapes has been elaborated, thus foundry engineer facing difficulty. RP pattern based investment casting overcomes the conventional ...

Gas Turbines used in fighter aircraft depend on starter units for initial starting as well as midair
restarting. These units in turn work on gas turbine principles having two distinct parts viz., Gas
Generator Turbine (GGT) stage and Free Power Turbine (FPT) stage. Generally, both these stages
consist of one set of Rotor and Stator castings having a number of highly twisted blades integrally cast
on a central hub. Investment casting is the standard method adopted for manufacture of these castings
which are made of nickel based super alloys, to meet stringent dimensional, metallurgical and
mechanical property specifications.
The tooling for the castings usually consists of a wax pattern mould/die (segmental die),
which yields a single aerofoil pattern segment. Multiple injections with investment casting wax are
carried out on this die and individual segments are then assembled using a dedicated fixture, using
highly skilled manpower. These assembled wax patterns are subjected to CMM inspection to
dimensionally qualify various critical parameters including blade geometry, individual blade
orientation, inter-blade spacing, hub/shroud diameters, etc. This method suffers from disadvantages of
high cycle time, high rate of rejection and costly CMM inspection, but tolerable during development
stage of these critical castings. For a production environment, however, an integral die wherein total
wax pattern assembly is achieved in a single injection would be desirable. Such a tool/die would be
very complex, having as many inserts as number of blades in the rotor, with added complication of
retracting these inserts simultaneously on a unique path without breaking/damaging the wax pattern.
Issues in developing such a die include component modeling, identification of retraction path, insert
design, insert manufacture, dimensional qualification of insert, assembly of die, etc., the list being
endless.
The paper presents such an effort at DMRL where CAD/CAM, CNC machining, CMM
inspection and Rapid Prototyping technologies have been synergized for successful development of an
integral tooling for rotor castings.

The effects of colloidal silica content, quantity of refractory filler material and the nature of electrolyte has been discussed on the properties of slurry and investment shell mould. A factorial 23 matrix was used to optimize the investment shell mould using colloidal silica binder.

This present study is concerned with the investigation of mechanical properties of copper alloy castings produced by investment casting process using Acrylonitrile Butadiene Styrene (ABS) as the pattern material and the Plaster of Paris as the mould material. The studies on the process parameters and the mechanical properties of the copper alloy casting have gained significance. The aim of this research is to investigate the effect of burning temperature, firing time and pouring temperature on surface hardness and dimensional accuracy of the end casts. The sample is using copper alloy as the material which is the combination of elements like copper and zinc. This research used two levels of three parameters which are burning temperature, firing time and pouring temperature of the alloy to investigate their effects on the surface hardness and dimensional accuracy of the end casts. Experiments were conducted as per Full Factorial with Design Expert software. The experimental analysis revealed that the high burning temperature, high firing time and high pouring temperature of the copper alloy can influence the mechanical properties of copper alloy casting result for hardness and dimensional accuracy of the samples.

– Investment casting also called the lost wax process or the precision casting process is very different from conventional casting process. Quality parameters are important considerations now a day in various fields where precision casting is required such as aerospace, defense equipment, automobile, medical and dental instrumentation and jewelries. The candidate in the present work has compared conventional casting method with investment casting method of same product on the basis of cost, quality and dimensional accuracy. The data is obtained by performing mentioned two methods experimentally in the workshop; result comparison between data is showing that investment casting gives high dimensional accuracy product with good surface quality. The initial step of any casting method is gating system design for casting. A good casting mostly depends on the correct gating design for achieving accurate casting product without time loss. So gating design is also performed for achieving dimensional accuracy and saving time. Pro CAST Manager is used to simulate the defects and for understanding solidification phenomenon at different nodes. So the Pro CAST is one of the effective tool for predefining the defects and improving the gating design, reducing these losses, saving time and cost and improved productivity.

The research aimed at the comparison of the old and modern jewellery and goldsmith's articles, based on the alloys and technologies used. The jewellery was cast taking the historical artefacts as models, using the old traditions and technologies. The jewellery manufacturer of old, not only had to master the jewellery-making technologies including casting, but also he had to have the knowledge concerning his raw material. An important aspect of it were the metal working properties showing off the decorative and plastic scope of the material. That is why, for ornament production, alloys were used more often than pure metals, because they had better technological properties. It is an important aspect of work then, to get to know the technology of creating gold elements and comparing them with the methods used nowadays, and also preparing our own jewellery project and implementing it, with the help of both traditional and computer-aided modern technology. The inspiration and knowledge came mainly from the historical artefacts coming from excavations at the Market Square in Krakow; the finds were obtained through the cooperation of the Foundry Faculty of AGH, the University of Science and Technology with the Research Team for The Main Market in Krakow. This is both research as well as a creative project. It presents original projects, leading to actual manufacturing of a ring, with the help of traditional foundry technologies, including the lost-wax casting method. The chemical content was analysed with the help of X-ray fluorescence spectroscopy and macroscopic observations of chosen rings made from copper alloys. Also macroscopic observations of other artefacts were conducted. Historical patterns of ornaments, starting form the 11th century up to the present times, have become the source material about the 'old' jewellery making and the starting point for creating a 'new' collection. The work describes consecutive stages of creating a ceramic mould, and it can become the source material for information and research concerning the artistic craftsmanship field.

The ceramic shells were fabricated with ceramic slurry containing yttria as filler material and colloidal silica binder. The slurry characteristics in terms of sedimentation and kinematic viscosity were measured. The green bending strength was determined to find the bonding strength of the ceramic shells. The yttria shells exhibit high strength for filler to binder ratio of 0.78 cc/ml.

The present work was intended to judge the influence of superheat and mould preheat temperature on the fluidity of 6xxx Al-alloys. The fluidity spirals were made using magnesia filler materials and the colloidal silica binder. The fluid increases with the increase of super heat and shell mould preheat temperature. The fluidity was higher for 6061 Al-alloy than that of 6013 Al-alloy.

Dip coating investment slurry composition is important parameter to judge the performance of ceramic shell moulding process. The paper presents the use of an industrial waste, namely coal flyash for the investment casting. Experiments have been conducted on the dip-coating slurry and shell moulds to examine their characteristics that enrich the ceramic shell moulding process from flyash. The results indicate substantial enhance in the quality of flyash shell moulds due to uniform slurry viscosity, low sedimentation rate, completion of electrostatic bonds and round particle shape.

The paper presents the reduction ofAl-12% Si alloy casting porosity in the lost wax process choosing right coating materials. The variable factors were type of flour, flour particle size, viscosity of slurry and grain fineness of stucco sand. The results were compared in respect of hot bending strength and hot permeability of ceramic shells and % volume porosity of castings. The analysis of the results was based on the response surface criteria. The response functions were determined for the indices. The casting porosity was not resulted due to the use of aluminium silicate as a flour material.

The ceramic shells were fabricated with ceramic slurry containing graphite as a filler material and colloidal silica binder. The linear expansion coefficient of graphite shells increases with temperature. The presence of a hard alpha case layer is observed beneath the surface of the casting.

The Investment casting (IC) method is now used to make all precision components in the medical, hydropower, defence, car, and other sectors. IC has a wide range of applications and is well-known for its ability to make complex near-net form items with great dimensional precision and surface polish. Various scholars are making ongoing efforts to investigate the topic of investment casting. This publication offers a comprehensive survey of the studies in this vast topic. It emphasises improvements in the earliest stages of the investment casting process. It focuses on pattern creation improvements, mould composition, casting materials, and typical flaws, as well as preventative actions.

This study characterizes the bronze jewellery recovered from the Lusatian culture urn-field in Mała Kępa (Chełmno land, Poland). Among many common ornaments (e.g. necklaces, rings, pins) the ones giving evidence of a steppe-styled inspiration (nail earrings) were also identified. With the dendritic microstructures revealed, the nail earrings prove the implementing of a lost-wax casting method, whereas some of the castings were further subjected to metalworking. The elemental composition indicates the application of two main types of bronze alloys: Cu-Sn and Cu-Sn-Pb. It has been established that the Lusatian metalworkers were familiar with re-melting the scrap bronze and made themselves capable of roasting the sulphide-rich ores. The collection from Mała Kępa has been described in terms of its structure and composition. The investigations were made by means of the energy dispersive X-ray fluorescence spectroscopy (ED-XRF), scanning electron microscopy (SEM) coupled with an energy di...

This study aimed to determine the effect of using acrylonitrile butadiene styrene in place of conventional wax material on treatment pattern removal in the investment casting process. There are three controllable process variables that can affect treatment pattern removal, which include temperature increase, holding time and the number of layers of ceramic shell that have been considered for comparison. Comparison among the effects of temperature increase, holding time and numbers of ceramic shell layers on the ceramic shell was analyzed using ANOVA. It was found that temperature increase (Tx), holding time (t) and number of layers of ceramic shell (N) contribute significantly to the length of the crack (l) on the ceramic shell. The crack in the ceramic shell's surface was analyzed using scanning electron microscope photos. Less layers number cause the increase of crack length. The combination between temperature upraise and longer holding time cause cracking delay. The experimental is conducted by using 3 (three) variants for each of layers number, temperature and holding time. The layers number is ranging between 7-9 layers. Temperature increase from room temperature until 1300 o C. The layers number variant is ranging between 180-300 seconds. It was concluded that a longer holding time will result in a more intact ceramic shell, as longer holding times yield short crack lengths.

Investment Casting (IC) is a producing method of high quality casting. It is useful to generate complex geometry in casting product, which cannot be achieved by forging, machining, or machining process with excessive material usage. Currently, IC pattern is made of wax. The wax melts away during the molten metal pouring. In the past, it was stipulated that once a foundry used a wax pattern of particular grades, that it could not be replaced by another grade. This was to avoid the risk of dimensional variety of patterns, coupled with a basic fear of change. The pattern wax compounds have been chosen by foundries with numerous considerations, such as: historical record; the wax the only suitable compound at the time; professional recommendation; and copying from another foundry. Inappropriate wax injector's parameter can create low quality patterns and a ceramic shell. Nowadays, there are wide ranges of material available as an alternative for the IC wax pattern, which in this paper initially highlighted using Acrylonitrile Butadiene Styrene (ABS) as a replacement of conventional pattern material. The pattern with ABS material can be created by Rapid Prototyping Machine (RPM) that is Fused Deposition Modeling (FDM) technology. The experimental outcomes are: there are cracks in the ceramic shell while using the smelting chemical method because ABS material pushed out the shell; perfect ceramic shell with ABS pattern smelting while using burnout method; and this method can reduce three of seven steps or more efficient about 42.85% of the existing IC process.

The Investment casting (IC) method is now used to make all precision components in the medical, hydropower, defence, car, and other sectors. IC has a wide range of applications and is well-known for its ability to make complex near-net form items with great dimensional precision and surface polish. Various scholars are making ongoing efforts to investigate the topic of investment casting. This publication offers a comprehensive survey of the studies in this vast topic. It emphasises improvements in the earliest stages of the investment casting process. It focuses on pattern creation improvements, mould composition, casting materials, and typical flaws, as well as preventative actions.

The ceramic shells were fabricated with ceramic slurry containing fused silica as filler material and colloidal silica binder. The shell characteristics in terms of hot bending strength and thermal expansion were measured. The non–linear nature of thermal expansion in the ceramic shells is on account of α to β phase transmission of stuccoing sand between 500 to 600C.  The ceramic shells which were sintered at 700C were observed to have cracks.

Design of gating system is an important factor in obtaining defect-free casting. One of the casting defects is a porosity caused by internal shrinkage in solidification process. Prediction of the internal shrinkage porosity in the femoral stem of commercially pure titanium (CP-Ti) is investigated based on the gating system design. The objective of this research is to get the best gating system between three gating system designs. Three gating system designs of the femoral stem were simulated in an investment casting method. The internal shrinkage porosity occurs on the largest part and near the ingate of the femoral stem. The gating system design that has ingates cross section area: 78.5; 157; and 128.5 mm 2 has the least of the internal shrinkage porosity. This design has the most uniform solidification in the entire of the femoral stem. An experiment is conducted to validate the simulation data. The results of internal shrinkage porosity in the three gating system designs in the simulation were compared with the experiment. Based on the comparison, the trend of internal shrinkage porosity at the three gating system designs in the simulation agrees with the experiment. The results of this study will aid in the elimination of casting defect.

This study aimed to determine the effect of using acrylonitrile butadiene styrene in place of conventional wax material on treatment pattern removal in the investment casting process. There are three controllable process variables that can affect treatment pattern removal, which include temperature increase, holding time and the number of layers of ceramic shell that have been considered for comparison. Comparison among the effects of temperature increase, holding time and numbers of ceramic shell layers on the ceramic shell was analyzed using ANOVA. It was found that temperature increase (Tx), holding time (t) and number of layers of ceramic shell (N) contribute significantly to the length of the crack (l) on the ceramic shell. The crack in the ceramic shell's surface was analyzed using scanning electron microscope photos. Less layers number cause the increase of crack length. The combination between temperature upraise and longer holding time cause cracking delay. The experimental is conducted by using 3 (three) variants for each of layers number, temperature and holding time. The layers number is ranging between 7-9 layers. Temperature increase from room temperature until 1300 o C. The layers number variant is ranging between 180-300 seconds. It was concluded that a longer holding time will result in a more intact ceramic shell, as longer holding times yield short crack lengths.

The characteristics dip-casting slurries judge the performance of investment casting process.  The paper presents a hypothesis on the bonding mechanism in the ceramic shells developed from coal flyash. Experiments have been carried out to study the effects of filler loading, aging and air-drying on the strength of shells. The results indicate substantial reduction in the sedimentation under operating conditions and enhancement in the shells strength.

The ceramic shells were fabricated with ceramic slurry containing rutile (titania) as filler material and colloidal silica binder. The shell characteristics in terms of hot bending strength and hot permeability were measured. The hot bending strength was found high at 500oC.  It was witnessed the removal of grain boundary defects, grain growth, and phase transformation to larger rutile nanocrystallites at 1000°C.

Design of gating system is an important factor in obtaining defect-free casting. One of the casting defects is a porosity caused by internal shrinkage in solidification process. Prediction of the internal shrinkage porosity in the femoral stem of commercially pure titanium (CP-Ti) is investigated based on the gating system design. The objective of this research is to get the best gating system between three gating system designs. Three gating system designs of the femoral stem were simulated in an investment casting method. The internal shrinkage porosity occurs on the largest part and near the ingate of the femoral stem. The gating system design that has ingates cross section area: 78.5; 157; and 128.5 mm 2 has the least of the internal shrinkage porosity. This design has the most uniform solidification in the entire of the femoral stem. An experiment is conducted to validate the simulation data. The results of internal shrinkage porosity in the three gating system designs in the simulation were compared with the experiment. Based on the comparison, the trend of internal shrinkage porosity at the three gating system designs in the simulation agrees with the experiment. The results of this study will aid in the elimination of casting defect.

This paper presents the adjustment process of a simulation model to improve the correlation between simulation results and parts industrially manufactured. It includes the data registration at foundry plant, the preliminary setup of the model and the later adjustment process to reach a correlation level according to the industrial necessities. The adjustment has been performed by means of inverse modelling. This technique uses thermal histories experimentally registered as base, and modifies the material properties and boundary conditions used in simulation until reaching a good correlation between numerical simulated cooling curves and they registered experimentally. The adjustment has been also focused on the shrinkage defects. The simulation model is a FEM model developed in commercial software specifically focused on metal casting simulation. The case of study is an investment casting process, vacuum poured, of a nickel base superalloy designated Hastelloy X. Usual in the manufacture of components for aeronautical turbines.

The achievement of reliable simulations, in the case of complex processes as is the investment casting, is not a trivial task. Their accuracy is significantly related with the knowledge of the material properties and boundary conditions involved, but the estimation of these values usually is highly complex. One helpful option to try to avoid these difficulties is the use of inverse modelling techniques, where experimental temperature measurements are used as base to correlate the simulation models. The research presented hereafter corresponds to the correlation of a finite element model of the investment casting process of two nickel base superalloys, Hastelloy X and Inconel 718. The simulation model has been developed in a commercial software focused specifically on metal casting simulation. The experimental measurements used as base for the adjustment, have been performed at industrial facilities. The methodology employed combines the use of an automatic tool for model correlation...