Design of Hydroxyapatite/Magnetite (HAP/Fe3O4) Based Composites Reinforced with ZnO and MgO for Biomedical Applications

Hydroxyapatite (HAP-- Ca 10(PO4 )6 (OH)2 ) is a biocompatible and bioactive material that is widely used for biomedical applications, especially in bone replacements. It has good load carrying capacity; however, it lacks antibacterial property. New bio-composites based on bovine hydroxyapatite doped with, magnetite iron oxide (HAP/ Fe3 O4 ) matrix reinforced with ZnO and MgO nanoparticles are proposed for biomedical applications that provide improved antibacterial activity with potential to be used in magnetic therapy. Microwave sintering was used to manufacture the composites. The microstructure evolution in these composites were studied by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Density, microhardness, compressive strength of the composites was measured and compared along with their magnetic properties. Finite element analysis simulations were performed for the compression tests

Experimental and numerical study of Al-Nb2Al composites via associated procedure of powder metallurgy and thixoforming

In this study powder metallurgy and thixoforming methods are used together to manufacture aluminum alloy based composite materials reinforced with Nb2Al particles and glass bubbles (GB). Fresh scrap recycled aluminum chips, AA7075 received mainly from Brazilian aeronautic industry, are used as the raw material. Processing parameters of the manufacturing techniques were optimized and the distribution of the reinforcing particles as well as their interfaces with the matrix were analyzed. The mechanical properties of the newly designed composite material were determined by compression and bending tests. Very detailed interface analysis and microstructure and fracture surface evaluations were performed by Scanning Electron Microscopy (SEM). The results indicate that the proposed combined powder metallurgy and thixoforming method yields metal matrix composites with good mechanical properties. A non-linear finite element model (three dimensional) was used to simulate the bending and compression behaviour of Al-Nb2Al composites. A subroutine, VUHARD, was written to use with ABAQUS to analyze the effect of thixoforming and sintering on the micro and macrostructure of the manufactured materials. Different ratios of reinforcing particulates (Nb2Al, Glass Bubbles) used in the experimental specimens were used in Representative Volume Element (RVE) for the microstructure modeling. Numerical models for the macrostructure were created using these micro-structures. It has been observed that there is a good agreement between numerical analysis and experimental results. Proposed process offers an original method for the production of newly designed composite material from recycled waste aluminum that can have a major impact on the energy consumption in the aluminum industry, and when enhanced with the numerical tools for simulation it can lead to the development of better performing materials for the aviation industry

Recycled “Al431 + A1050” Based Composites Reinforced with “TiC” Ceramic Powders for Aeronautical Applications

In this study, a novel recycled Al 431 + 1050 based composites reinforced with “TiC” were designed for aeronautical applications with high resistant structure against to choc and static loading under service conditions. Static/dynamic compression behaviours of these composites were evaluated. Basically, laboratory-scale test samples were produced using combined “sinter + forging” production methods. Al 431 + 1050, a mixture of recycled and modified aluminium alloys, was used as the main matrix material. Different proportions of TiC (10, 15 and 20 wt %) were used as a major reinforcement element. As minor reinforcements, Mo and Cu metal powders and a small amount of Graphene Nano Platelets, (GNPs), and Alumina, (γ-Al2O3) fibre were used to compare their influence on the mechanical properties of these hybrid composite structures

Design of Copper and γ-Alumina Reinforced Recycled Aluminium Matrix Composites through Sintering + Forging

The present work, reviews the toughening mechanisms and microstructural analyses of recycled aluminium matrix composites reinforced with γ-alumina and pure recycled copper. This composite was manufactured by sintering and sinter + forging called the combined process. Static compression, 3-point bending, impact (drop-weight) tests were conducted to evaluate mechanical response of the composites. Additionally, wear and creep tests were carried out with a nanoindenter to evaluate wear and time dependent behaviour of this composite. Detailed analyses of microstructure of the composites was performed with Scanning Electron Microscopy (SEM) supported by EDS analyses. The results showed that, the composites have homogeneous structure without porosity and very homogeneous distribution of fine γ-alumina (Al O ) and copper particles. Sinter + forging process yielded a material that had higher strength, hardness and better resistance to wear. This composite will be targeted for linkage applications where high toughness and high surface damage resistance is required

Recycled Niobium-Aluminium (Nb2Al) Intermetallics Based Composite Design: An Experimental and Numerical Approach for Toughening Mechanism

In this project, design of niobium-aluminium (Nb2Al) intermetallics based composites is proposed by using the fresh scrap recycled niobium and aluminium alloy AA7075. These compositions will be the target for aeronautical engineering applications for high temperature service conditions. Manufacturing of these composites is an important engineering case for tailored behaviour of the composites produced through combined method of powder metallurgy route; sintering followed by forging. Different materials and operational (process) parameters will be used for optimization of the compositions. All of the analyses will be devoted to the static (compression, 3-point bending) test conditions. Microstructure analyses (matrix/interface) will be carried out by Scanning Electron Microscope (SEM). At this stage of the project, the primary objective would be to establish a continuum-based material model in order to capture the macroscopic behaviour of the targeted composite materials and numerically reproduce the results from the basic characterization tests (3P bending). The model will be implemented for Finite Element Analysis Software ABAQUS/Explicit as a user subroutine VUMAT for explicit nonlinear finite element calculations. The second step would be modelling of the microstructure of the proposed hybrid Nb2Al based composites and simulate the behaviour of several RVEs and see the effect of the sintered-forging and different ratios of reinforcing particulates

Experimental and numerical study of Al-Nb 2 Al composites via associated procedure of powder metallurgy and thixoforming

In this study powder metallurgy and thixoforming methods are used together to manufacture aluminum alloy based composite materials reinforced with Nb 2 Al particles and glass bubbles (GB). Fresh scrap recycled aluminum chips, AA7075 received mainly from Brazilian aeronautic industry, are used as the raw material. Processing parameters of the manufacturing techniques were optimized and the distribution of the reinforcing particles as well as their interfaces with the matrix were analyzed. The mechanical properties of the newly designed composite material were determined by compression and bending tests. Very detailed interface analysis and microstructure and fracture surface evaluations were performed by Scanning Electron Microscopy (SEM). The results indicate that the proposed combined powder metallurgy and thixoforming method yields metal matrix composites with good mechanical properties. A non-linear finite element model (three dimensional) was used to simulate the bending and compression behaviour of Al-Nb 2 Al composites. A subroutine, VUHARD, was written to use with ABAQUS to analyze the effect of thixoforming and sintering on the micro and macrostructure of the manufactured materials. Different ratios of reinforcing particulates (Nb 2 Al, Glass Bubbles) used in the experimental specimens were used in Representative Volume Element (RVE) for the microstructure modeling. Numerical models for the macrostructure were created using these micro-structures. It has been observed that there is a good agreement between numerical analysis and experimental results. Proposed process offers an original method for the production of newly designed composite material from recycled waste aluminum that can have a major impact on the energy consumption in the aluminum industry, and when enhanced with the numerical tools for simulation it can lead to the development of better performing materials for the aviation industry. © 2018Conselho Nacional de Desenvolvimento Científico e Tecnológico Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorThe authors acknowledge the financial support provided by CNPq – CAPES /-SP-BRAZIL in the frame of common project carried out by Supmeca-Paris, UNICAMP-Campinas/SP-Brazil and Michigan Tech-USA

Design of Recycled Alumix-123 Based Composites Reinforced with γ-Al2O3 through Combined Method; Sinter + Forging

Aluminium Metal Matrix Composites (AMMCs) have very light weight, high strength, and show better resistance to corrosion, oxidation, and wear. Impact resistance is an especially important property of these AMMCs which is essential for automotive applications. In this study, recycled aluminium matrix composites were designed through the powder metallurgy route. As matrix, fresh scrap aluminium chips (Alumix-123), by-product of machining coming from the French aeronautical company, were used. Fine -alumina particles (γ-Al O , 10 wt %), were used as main reinforcement element for the present work. As secondary reinforcements, Mo and Cu were added in the matrix. In this study, a typical low cost but high performance metal matrix composite was designed by using recycled aluminum chips (Alumix-123). This process comprises of the mixing, blending and compacting of aluminum chips through press moulding and pre-sintering and finally forging. In the final stage, material parameters were optimized for improving physical and mechanical properties of these composites. Further, the influence of reinforcement’s type and content on the mechanical properties has also been reviewed and discussed. Damping capacities and damage were analysed by drop weight and quasi static compression tests. Microstructures were analysed by the Scanning Electron Microscope (SEM)

Design of Recycled Thin Sheet “Ti-Al” Based Composites Reinforced with AA1050, Boron, TiB2, TiC, and B4C Through Hot-Forged Bonding

In the frame of the common research project, the mechanical behaviour of recycled thin sheet Ti-Al based composites reinforced with scrap pure aluminium (AA1050) and boron, B reinforcement elements have been used with thin Ti-Al sheet recycled by hot forging method. The effects of chemical bonds during the production of these multifunctional sandwich composite structures were analyzed by 3-point bending tests to evaluated hyper elasticity behaviour. The same idea has been carried out this time on the Ti-Al based composites performed by sintered + forging through the powder metallurgy route by using different reinforcements such as TiB , TiC, and B C. Quasi static compression and low velocity impact (drop weight) tests have been performed on the sintered + forging specimens with a drop tower to observe the response of theses composites under the dynamic loading conditions. Interface and microstructure of these composites have been evaluated by Scanning Electron Microscope (SEM)

New Design of Composites from Fresh Scraps of Niobium for Tribological Applications

Niobium is the best and excellent metal for many different industrial applications. Europe has not a Niobium reserve whereas Brazil has a major Niobium mining and produce %90 of the Niobium in the world as a raw material. However, the processing of this metal beginning from mining up to the advance processing for the real manufacturing engineering applications is very expensive and require a sophisticated equipment and investment. However, very huge amount of scraps of the niobium coming from manufacturing of the pieces is not reprocessed efficiently as valuable and economic way because quasi all of the scarps goes to the waste. The niobium scraps as an important secondary source of the raw materials should be evaluated for the manufacturing of the new composite design. As not possible to extract in an economical way, the recycling of niobium could be a sustainable occasion for the industrial applications. The present work review of the efficient and sustainable recycling of the fresh scraps of niobium metal in the frame of the common research project carried out between UNICAMP-Brazil and SUPMECA-France. In this work, aluminium (AA 7075) matrix composites were designed by using the combined method, sinter + forging through the powder metallurgy route. Niobium powder obtained fresh scrap by using high energy milling were used as main reinforcement element for the present work. As secondary reinforcements, fine Ni–Al intermetallic, TiB2, TiC, B4C and Mo powders were added in the matrix in order to prepare five different compositions. This process consists of the mixing, blending by high energy milling and compacting of the final composition through the combined method, sinter + forging. In the final stage, material parameters were optimized for improving physical and mechanical properties of these composites. Damping capacities and damage were analyzed by drop weight and quasi static compression, scratch wearing tests, etc. Microstructures were analyzed by the Scanning Electron Microscope (SEM)

Design of Low Composites from Recycled Copper + Aluminium Chips for Tribological Applications

In this work, a special copper aluminium matrix composite (ACMMCs) obtained from the fresh scrap – chips of AA7075 and- pure electrolytic copper were designed through combined method of powder metallurgy and sinter + Forging. First of all, Al-Cu matrix was doped with ZnO after the ball milling with two basic reinforcements (Nb2Al– SiC, etc.) was carried out during the 4 h. A basic composition was prepared depending on the doping percentage of ZnO as 30 wt%. Mechanical and physical properties of this composite designed here can be improved with the doping process followed by combined method of powder compacted specimens and doping volume fractions. The surface scratch tests and micro-hardness results were compared according to the optimization conditions of the doping and the reinforcement. Static compression and impact-drop weight tests were carried out. The microstructure and damage analyses have been carried out by Scanning Electron Microscope (SEM)