This paper deals with the possibility of reducing carbon content by heat treatment in reactive at... more This paper deals with the possibility of reducing carbon content by heat treatment in reactive atmospheres in order to improve plastic deformations properties of steel sheets. The heat treatment involves a decarburation annealing after a cold rolling, as opposed to the traditional process that performs the heat treatment in non-reactive atmospheres. Some of the most relevant variables were studied. For this, commercial hot rolling steel sheets were cold rolled with different grades of cold reduction (60%, 70% and 80%). The recrystallization temperature and the decarburation kinetics were determined by heat treatments performed at temperatures varying between 600 and 700ºC, for variable lengths of time up to 2 hours. The grain size evolution was monitored by metallography. In order to analyse the plastic properties of the treated sheets, the n and r coefficients were obtained by tension tests and the sheet texture was determined by X-ray diffraction.
En los ultimos tiempos se ha experimentado un aumento en la demanda de aleaciones de magnesio en ... more En los ultimos tiempos se ha experimentado un aumento en la demanda de aleaciones de magnesio en la industria aeroespacial y automotriz debido a su bajo peso. La reduccion de peso se considera la mejor opcion para disminuir el consumo de combustible y las emisiones de CO 2 . El presente trabajo tuvo como objetivo el desarrollo de un metodo que permita la recuperacion de la viruta de aleacion de magnesio AZ91D, producto del mecanizado de autopartes mediante tecnicas de pulvimetalurgia, con la finalidad de poderlo aplicar en componentes estructurales aeroespaciales. Las variables analizadas fueron: granulometria del polvo, presion de compactacion y condiciones del sinterizado. Se determino experimentalmente el valor optimo de cada variable evaluando la resistencia maxima a la compresion del producto final. Luego se utilizo este material como matriz para la fabricacion de un material compuesto de matriz metalica utilizando como refuerzo materiales ceramicos y metalicos. La maxima resi...
This paper presents what has been done in the project entitled "Biodegradable coatings on AZ91D, ... more This paper presents what has been done in the project entitled "Biodegradable coatings on AZ91D, assessment of performance in simulated physiological fluid", in which three types of coatings are investigated to reduce the corrosion of the metal in a biological medium. In this first part of the work, it was carried out a chemical conversion by immersion in order to deposit hydroxyapatite (HAp) on the surface of the magnesium alloy parts, manufactured by powder metallurgy. For this purpose, a hydrothermal treatment of the samples was conducted in EDTA-Ca and KH2PO4 solution for 4h. The coatings were observed by confocal microscopy and tested through surface adhesion test and hydrogen release test in 0.9 %w/v. NaCl solution at 37 °C. It was obtained a conversion on the surface with encouraging results. A deposition of HAp on the surface and a 95,4% decrease in the corrosion rate of coated samples were obtained and it is expected to be further improved. For this, the investigation must continue, delving into the factors that influence this behavior.
Institute of Electrical and Electronics Engineers, 2013
Hydroxyapatite (Ca10(PO4)6(OH)2 is the material used to improve osseointegration of implants in h... more Hydroxyapatite (Ca10(PO4)6(OH)2 is the material used to improve osseointegration of implants in humans. Traditionally Ti-based implant is coated with hydroxyapatite, but this presents several problems such as, low fracture toughness of hydroxyapatite, generation of interfacial cracks during the deposition step and low adhesion ceramic /metal. Furthermore some studies reported that some excellent Ti-HA bio-composites could be fabricated by the powder metallurgy (PM) technology. In present study it was investigate the cytotoxicity of coralline and bovine hydroxyapatite. Topography of Ti-HA composites obtained by powder metallurgy was evaluated by scanning electron microscopy. The results showed that HA samples analyzed did not affect cell viability. Furthermore, a good integration of HA to the matrix of Ti was observed by microscopy studiesFil: Comin, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Reyna Musso, Laura A.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Electrónica. Laboratorio de Investigación Aplicada y Desarrollo; ArgentinaFil: Cid, Mariana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Oldani, Carlos Rodolfo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Salvatierra, Nancy Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentin
Este trabajo estudia un proceso para la fabricación de titanio poroso por pulvimetalúrgia, median... more Este trabajo estudia un proceso para la fabricación de titanio poroso por pulvimetalúrgia, mediante la mezcla de TiH2, resina acrílica y un monómero líquido en distintas proporciones; así como el control del tamaño, forma y distribución de los poros para obtener implantes biomédicos osteointegrados con las características deseadas. Se presenta el estudio de las estructuras porosas mediante técnicas de microscopía óptica y procesado de imágenes por software y se discute sobre los resultados obtenidos del tamaño, forma y distribución de los poros para la correcta regeneración ósea.
Hundreds of people worldwide die or are severely maimed in collisions during traffic accidents, d... more Hundreds of people worldwide die or are severely maimed in collisions during traffic accidents, due to the energy transmitted to the passengers on impact. A dissipation of said energy is necessary to minimize it's effects, which can be achieved through absorbers. In recent years, metallic foams have started to be considered as energy absorbers. Metallic foams are relatively unknown structural materials, but with huge potential for applications where low weight but high rigidity are of primary interest. The use of ultralight magnesium (Mg) or magnesium alloy foams has two main advantages: less weight (more vehicle efficiency and less pollution) and impact energy absorption (less harm to passengers on board the vehicle). The machining of gearboxes made out of AZ91D magnesium alloy, generates large amounts of oilcontaminated metallic shavings. In this work, powder metallurgy is used as a recycling method of the AZ91 alloy. There were studied the conditions needed for obtaining meta...
An ideal biomaterial is expected to exhibit properties such as a very high biocompatibility, that... more An ideal biomaterial is expected to exhibit properties such as a very high biocompatibility, that is, no adverse tissue response. Also, it must have a density as low as that of bone, high mechanical strength and fatigue resistance, low elastic modulus and good wear resistance. It is very difficult to combine all these properties in only one material. Some metals are used as biomaterials due to their excellent mechanical properties and good biocompatibility. Since the metallic bonds in these materials are essentially non-directional, the position of the metals ions can be altered without destroying the crystal structure, resulting in a plastically deformable solid. This is also an advantage when thinking about the device manufacture technology. The principal disadvantage of metals is its corrosion tendency in an in-vivo environment. Most metals can only be tolerated by the human body in small amounts even as metallic ions. The consequences of corrosion are the disintegration of the material implant, which will weaken the implant and the harmful effect of corrosion products on the surrounding tissues and organs. Some metals are used as passive substitutes for hard tissue replacement such as total hip and knee joints, for fracture healing aids as bone plates and screws, spinal fixation devices and dental implants. Some metallic alloys are used for more active roles, as actuators such as vascular stents, and orthodontic archwires. Metallic biomaterials can be conveniently grouped in the following categories: Stainless steel Cobalt base alloys Titanium base alloys Specialty metallic alloys Examples of ASTM standards for some of these metallic biomaterials are shown in Table 1. The first metal alloy developed specifically for human use was the "vanadium steel" but it was no longer used in implants because its corrosion resistance is inadequate in vivo. Later in the 1950s, 18-8sMo with very low carbon content (known as 316L) stainless steel was introduced and is actually widely used for implant fabrication. This alloy has a very good resistance to chloride solutions and poor sensitization. The castable CoCrMo alloy has been used for many decades in dentistry and, relatively recently, in making artificial joints. The wrought CoNiCrMo alloy is relatively new, now used for making the stems of prostheses for heavily loaded joints such as the knee and hip. Both alloys have excellent corrosion resistance.
Fil: Salvatierra, Nancy Alicia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centr... more Fil: Salvatierra, Nancy Alicia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Biologicas y Tecnologicas. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Fisicas y Naturales. Instituto de Investigaciones Biologicas y Tecnologicas; Argentina
In a previous work a finite elements model was constructed to simulate a fatigue assay according ... more In a previous work a finite elements model was constructed to simulate a fatigue assay according to the norm IRAM 9422-3. Three materials were studied, two of them are the most used in this type of implant (Stainless steel 3161 and alloy T16A14V) and the third was a new developed titanium alloy (Ti35Nb7Zr5Ta). Static loads were applied to the model according to the highest requirements of the norm and the stress – strain distribution were determined. In this study a simplified analysis of the material's fatigue was done according to the previous work. The best behavior of the titanium alloys vs. the stainless steel was evident. With the objective of studying the behavior of both: the implant and the femur bone, new finite elements models were realized, in which the presence of the bone was considered. Inside the bone, the femoral component of the implant was placed in a similar way of a cemented prosthesis in a total hip arthroplasty. The advantage of the titanium implant related to the stainless steel one, was very clear.
It has proposed the use of porous titanium to reduce the problem of mechanical incompatibility, w... more It has proposed the use of porous titanium to reduce the problem of mechanical incompatibility, which occurs between such material used in implants and bone. The pores introduction in titanium decreases its elastic modulus by bringing it closer to that of both cortical and trabecular bones. This paper describes titanium fabrication by powder metallurgy with longitudinal porosity gradient, using as space holder material, ammonium hydrogen carbonate, in different proportions, mixed with titanium hydride powder. After layered uniaxial compaction and subsequent sintering at 1150 °C, cylinders with gradual longitudinal porosity 2 % - 30 %, 2 % - 60 %, 30 % - 60 % and 2 % - 30 % - 60 % were obtained. Microstructure, size, shape and pore distribution, elasticity modulus and yield stress were analyzed in the samples. The results indicate that by the method studied, it is possible to obtain sinterized samples with porosity gradient, structural continuity between the different porous layers, ...
This paper presents the first stages in the development of a composite material of metal and sili... more This paper presents the first stages in the development of a composite material of metal and silicone that can be used for 3d printing. The purpose of this project is to obtain a metallic object. This is achieved by printing using the composite material and sintering the object, in order to eliminate silicone particles. The motivation for the project is to offer an alternative for the current methods of printing metal, in particular selective laser sintering, since it is expensive and therefore, prevents a wider use of this technology.
Se trata de un trabajo de divulgacion en el que se brinda un panorama del desarrollo del titanio ... more Se trata de un trabajo de divulgacion en el que se brinda un panorama del desarrollo del titanio (Ti) y sus aleaciones con aplicacion en implantes oseos. El uso de biomateriales para reconstruir partes danadas del cuerpo humano es una realidad y para ello los materiales deben cumplir una serie de exigencias. Para el reemplazo de partes de la estructura osea se requiere de protesis o implantes de materiales que soporten los esfuerzos aplicados y que ademas, sean biocompatibles, es decir, que sean aceptados biologicamente. Estas condiciones las cumplen muy pocos metales, no pudiendose utilizar otros materiales como los ceramicos o los polimeros. El titanio presenta una clara ventaja sobre los otros biometales y es por eso la gran cantidad de estudios que se realizan para mejorar sus prestaciones como material de implante en el cuerpo humano. El recorrido se presenta a partir de las dificultades que presenta el material en cuanto a biocompatibilidad mecanica y se muestran los principal...
The development of microstructural damage in SiC fibre (Nicalon®) reinforced glass matrix composi... more The development of microstructural damage in SiC fibre (Nicalon®) reinforced glass matrix composites subjected to different mechanical and thermal loads was investigated by assessing the change of the thermal expansion coefficient and the resistance to impact loads of the composites. The thermal expansion coefficient, measured by dilatometry after thermal shock tests from 650 °C to room temperature, was found to
Hydroxyapatite (Ca 10 (PO 4) 6 (OH) 2 is the material used to improve osseointegration of implant... more Hydroxyapatite (Ca 10 (PO 4) 6 (OH) 2 is the material used to improve osseointegration of implants in humans. Traditionally Ti-based implant is coated with hydroxyapatite, but this presents several problems such as, low fracture toughness of hydroxyapatite, generation of interfacial cracks during the deposition step and low adhesion ceramic /metal. Furthermore some studies reported that some excellent Ti-HA bio-composites could be fabricated by the powder metallurgy (PM) technology. In present study it was investigate the cytotoxicity of coralline and bovine hydroxyapatite. Topography of Ti-HA composites obtained by powder metallurgy was evaluated by scanning electron microscopy. The results showed that HA samples analyzed did not affect cell viability. Furthermore, a good integration of HA to the matrix of Ti was observed by microscopy studies
Work with experimental animals to perform biocompatibility tests in vivo, requires compliance wit... more Work with experimental animals to perform biocompatibility tests in vivo, requires compliance with various protocols. In addition, the use of animals for study has a number of ethical and legal implications that must be taken into account when planning experiences. In this paper we analyze the protocols that must be taken into account in Argentina for experimentation with laboratory animals. The results of in vivo implantation tests using Ti (TiD), porous titanium (TiP) and titanium-hydroxyapatite (TiHA) samples, obtained by the powder metallurgical process, in Wistar rats are also shown. The procedures developed for animal selection, surgical procedure and post-surgical control were adequate. Good adhesion of the bone to the surface of the implants could be verified and also a start of new bone growth in the pores of the porous implants.
This paper deals with the possibility of reducing carbon content by heat treatment in reactive at... more This paper deals with the possibility of reducing carbon content by heat treatment in reactive atmospheres in order to improve plastic deformations properties of steel sheets. The heat treatment involves a decarburation annealing after a cold rolling, as opposed to the traditional process that performs the heat treatment in non-reactive atmospheres. Some of the most relevant variables were studied. For this, commercial hot rolling steel sheets were cold rolled with different grades of cold reduction (60%, 70% and 80%). The recrystallization temperature and the decarburation kinetics were determined by heat treatments performed at temperatures varying between 600 and 700ºC, for variable lengths of time up to 2 hours. The grain size evolution was monitored by metallography. In order to analyse the plastic properties of the treated sheets, the n and r coefficients were obtained by tension tests and the sheet texture was determined by X-ray diffraction.
En los ultimos tiempos se ha experimentado un aumento en la demanda de aleaciones de magnesio en ... more En los ultimos tiempos se ha experimentado un aumento en la demanda de aleaciones de magnesio en la industria aeroespacial y automotriz debido a su bajo peso. La reduccion de peso se considera la mejor opcion para disminuir el consumo de combustible y las emisiones de CO 2 . El presente trabajo tuvo como objetivo el desarrollo de un metodo que permita la recuperacion de la viruta de aleacion de magnesio AZ91D, producto del mecanizado de autopartes mediante tecnicas de pulvimetalurgia, con la finalidad de poderlo aplicar en componentes estructurales aeroespaciales. Las variables analizadas fueron: granulometria del polvo, presion de compactacion y condiciones del sinterizado. Se determino experimentalmente el valor optimo de cada variable evaluando la resistencia maxima a la compresion del producto final. Luego se utilizo este material como matriz para la fabricacion de un material compuesto de matriz metalica utilizando como refuerzo materiales ceramicos y metalicos. La maxima resi...
This paper presents what has been done in the project entitled "Biodegradable coatings on AZ91D, ... more This paper presents what has been done in the project entitled "Biodegradable coatings on AZ91D, assessment of performance in simulated physiological fluid", in which three types of coatings are investigated to reduce the corrosion of the metal in a biological medium. In this first part of the work, it was carried out a chemical conversion by immersion in order to deposit hydroxyapatite (HAp) on the surface of the magnesium alloy parts, manufactured by powder metallurgy. For this purpose, a hydrothermal treatment of the samples was conducted in EDTA-Ca and KH2PO4 solution for 4h. The coatings were observed by confocal microscopy and tested through surface adhesion test and hydrogen release test in 0.9 %w/v. NaCl solution at 37 °C. It was obtained a conversion on the surface with encouraging results. A deposition of HAp on the surface and a 95,4% decrease in the corrosion rate of coated samples were obtained and it is expected to be further improved. For this, the investigation must continue, delving into the factors that influence this behavior.
Institute of Electrical and Electronics Engineers, 2013
Hydroxyapatite (Ca10(PO4)6(OH)2 is the material used to improve osseointegration of implants in h... more Hydroxyapatite (Ca10(PO4)6(OH)2 is the material used to improve osseointegration of implants in humans. Traditionally Ti-based implant is coated with hydroxyapatite, but this presents several problems such as, low fracture toughness of hydroxyapatite, generation of interfacial cracks during the deposition step and low adhesion ceramic /metal. Furthermore some studies reported that some excellent Ti-HA bio-composites could be fabricated by the powder metallurgy (PM) technology. In present study it was investigate the cytotoxicity of coralline and bovine hydroxyapatite. Topography of Ti-HA composites obtained by powder metallurgy was evaluated by scanning electron microscopy. The results showed that HA samples analyzed did not affect cell viability. Furthermore, a good integration of HA to the matrix of Ti was observed by microscopy studiesFil: Comin, Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Reyna Musso, Laura A.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Electrónica. Laboratorio de Investigación Aplicada y Desarrollo; ArgentinaFil: Cid, Mariana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Oldani, Carlos Rodolfo. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Salvatierra, Nancy Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentin
Este trabajo estudia un proceso para la fabricación de titanio poroso por pulvimetalúrgia, median... more Este trabajo estudia un proceso para la fabricación de titanio poroso por pulvimetalúrgia, mediante la mezcla de TiH2, resina acrílica y un monómero líquido en distintas proporciones; así como el control del tamaño, forma y distribución de los poros para obtener implantes biomédicos osteointegrados con las características deseadas. Se presenta el estudio de las estructuras porosas mediante técnicas de microscopía óptica y procesado de imágenes por software y se discute sobre los resultados obtenidos del tamaño, forma y distribución de los poros para la correcta regeneración ósea.
Hundreds of people worldwide die or are severely maimed in collisions during traffic accidents, d... more Hundreds of people worldwide die or are severely maimed in collisions during traffic accidents, due to the energy transmitted to the passengers on impact. A dissipation of said energy is necessary to minimize it's effects, which can be achieved through absorbers. In recent years, metallic foams have started to be considered as energy absorbers. Metallic foams are relatively unknown structural materials, but with huge potential for applications where low weight but high rigidity are of primary interest. The use of ultralight magnesium (Mg) or magnesium alloy foams has two main advantages: less weight (more vehicle efficiency and less pollution) and impact energy absorption (less harm to passengers on board the vehicle). The machining of gearboxes made out of AZ91D magnesium alloy, generates large amounts of oilcontaminated metallic shavings. In this work, powder metallurgy is used as a recycling method of the AZ91 alloy. There were studied the conditions needed for obtaining meta...
An ideal biomaterial is expected to exhibit properties such as a very high biocompatibility, that... more An ideal biomaterial is expected to exhibit properties such as a very high biocompatibility, that is, no adverse tissue response. Also, it must have a density as low as that of bone, high mechanical strength and fatigue resistance, low elastic modulus and good wear resistance. It is very difficult to combine all these properties in only one material. Some metals are used as biomaterials due to their excellent mechanical properties and good biocompatibility. Since the metallic bonds in these materials are essentially non-directional, the position of the metals ions can be altered without destroying the crystal structure, resulting in a plastically deformable solid. This is also an advantage when thinking about the device manufacture technology. The principal disadvantage of metals is its corrosion tendency in an in-vivo environment. Most metals can only be tolerated by the human body in small amounts even as metallic ions. The consequences of corrosion are the disintegration of the material implant, which will weaken the implant and the harmful effect of corrosion products on the surrounding tissues and organs. Some metals are used as passive substitutes for hard tissue replacement such as total hip and knee joints, for fracture healing aids as bone plates and screws, spinal fixation devices and dental implants. Some metallic alloys are used for more active roles, as actuators such as vascular stents, and orthodontic archwires. Metallic biomaterials can be conveniently grouped in the following categories: Stainless steel Cobalt base alloys Titanium base alloys Specialty metallic alloys Examples of ASTM standards for some of these metallic biomaterials are shown in Table 1. The first metal alloy developed specifically for human use was the "vanadium steel" but it was no longer used in implants because its corrosion resistance is inadequate in vivo. Later in the 1950s, 18-8sMo with very low carbon content (known as 316L) stainless steel was introduced and is actually widely used for implant fabrication. This alloy has a very good resistance to chloride solutions and poor sensitization. The castable CoCrMo alloy has been used for many decades in dentistry and, relatively recently, in making artificial joints. The wrought CoNiCrMo alloy is relatively new, now used for making the stems of prostheses for heavily loaded joints such as the knee and hip. Both alloys have excellent corrosion resistance.
Fil: Salvatierra, Nancy Alicia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centr... more Fil: Salvatierra, Nancy Alicia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Investigaciones Biologicas y Tecnologicas. Universidad Nacional de Cordoba. Facultad de Ciencias Exactas, Fisicas y Naturales. Instituto de Investigaciones Biologicas y Tecnologicas; Argentina
In a previous work a finite elements model was constructed to simulate a fatigue assay according ... more In a previous work a finite elements model was constructed to simulate a fatigue assay according to the norm IRAM 9422-3. Three materials were studied, two of them are the most used in this type of implant (Stainless steel 3161 and alloy T16A14V) and the third was a new developed titanium alloy (Ti35Nb7Zr5Ta). Static loads were applied to the model according to the highest requirements of the norm and the stress – strain distribution were determined. In this study a simplified analysis of the material's fatigue was done according to the previous work. The best behavior of the titanium alloys vs. the stainless steel was evident. With the objective of studying the behavior of both: the implant and the femur bone, new finite elements models were realized, in which the presence of the bone was considered. Inside the bone, the femoral component of the implant was placed in a similar way of a cemented prosthesis in a total hip arthroplasty. The advantage of the titanium implant related to the stainless steel one, was very clear.
It has proposed the use of porous titanium to reduce the problem of mechanical incompatibility, w... more It has proposed the use of porous titanium to reduce the problem of mechanical incompatibility, which occurs between such material used in implants and bone. The pores introduction in titanium decreases its elastic modulus by bringing it closer to that of both cortical and trabecular bones. This paper describes titanium fabrication by powder metallurgy with longitudinal porosity gradient, using as space holder material, ammonium hydrogen carbonate, in different proportions, mixed with titanium hydride powder. After layered uniaxial compaction and subsequent sintering at 1150 °C, cylinders with gradual longitudinal porosity 2 % - 30 %, 2 % - 60 %, 30 % - 60 % and 2 % - 30 % - 60 % were obtained. Microstructure, size, shape and pore distribution, elasticity modulus and yield stress were analyzed in the samples. The results indicate that by the method studied, it is possible to obtain sinterized samples with porosity gradient, structural continuity between the different porous layers, ...
This paper presents the first stages in the development of a composite material of metal and sili... more This paper presents the first stages in the development of a composite material of metal and silicone that can be used for 3d printing. The purpose of this project is to obtain a metallic object. This is achieved by printing using the composite material and sintering the object, in order to eliminate silicone particles. The motivation for the project is to offer an alternative for the current methods of printing metal, in particular selective laser sintering, since it is expensive and therefore, prevents a wider use of this technology.
Se trata de un trabajo de divulgacion en el que se brinda un panorama del desarrollo del titanio ... more Se trata de un trabajo de divulgacion en el que se brinda un panorama del desarrollo del titanio (Ti) y sus aleaciones con aplicacion en implantes oseos. El uso de biomateriales para reconstruir partes danadas del cuerpo humano es una realidad y para ello los materiales deben cumplir una serie de exigencias. Para el reemplazo de partes de la estructura osea se requiere de protesis o implantes de materiales que soporten los esfuerzos aplicados y que ademas, sean biocompatibles, es decir, que sean aceptados biologicamente. Estas condiciones las cumplen muy pocos metales, no pudiendose utilizar otros materiales como los ceramicos o los polimeros. El titanio presenta una clara ventaja sobre los otros biometales y es por eso la gran cantidad de estudios que se realizan para mejorar sus prestaciones como material de implante en el cuerpo humano. El recorrido se presenta a partir de las dificultades que presenta el material en cuanto a biocompatibilidad mecanica y se muestran los principal...
The development of microstructural damage in SiC fibre (Nicalon®) reinforced glass matrix composi... more The development of microstructural damage in SiC fibre (Nicalon®) reinforced glass matrix composites subjected to different mechanical and thermal loads was investigated by assessing the change of the thermal expansion coefficient and the resistance to impact loads of the composites. The thermal expansion coefficient, measured by dilatometry after thermal shock tests from 650 °C to room temperature, was found to
Hydroxyapatite (Ca 10 (PO 4) 6 (OH) 2 is the material used to improve osseointegration of implant... more Hydroxyapatite (Ca 10 (PO 4) 6 (OH) 2 is the material used to improve osseointegration of implants in humans. Traditionally Ti-based implant is coated with hydroxyapatite, but this presents several problems such as, low fracture toughness of hydroxyapatite, generation of interfacial cracks during the deposition step and low adhesion ceramic /metal. Furthermore some studies reported that some excellent Ti-HA bio-composites could be fabricated by the powder metallurgy (PM) technology. In present study it was investigate the cytotoxicity of coralline and bovine hydroxyapatite. Topography of Ti-HA composites obtained by powder metallurgy was evaluated by scanning electron microscopy. The results showed that HA samples analyzed did not affect cell viability. Furthermore, a good integration of HA to the matrix of Ti was observed by microscopy studies
Work with experimental animals to perform biocompatibility tests in vivo, requires compliance wit... more Work with experimental animals to perform biocompatibility tests in vivo, requires compliance with various protocols. In addition, the use of animals for study has a number of ethical and legal implications that must be taken into account when planning experiences. In this paper we analyze the protocols that must be taken into account in Argentina for experimentation with laboratory animals. The results of in vivo implantation tests using Ti (TiD), porous titanium (TiP) and titanium-hydroxyapatite (TiHA) samples, obtained by the powder metallurgical process, in Wistar rats are also shown. The procedures developed for animal selection, surgical procedure and post-surgical control were adequate. Good adhesion of the bone to the surface of the implants could be verified and also a start of new bone growth in the pores of the porous implants.
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Papers by Carlos Oldani