56 documents found, page 1 of 6
Microstructure, mechanical properties and corrosion behaviour of Ti6Al4V/Al2O3 ...
Alves, Alexandra Manuela Vieira Cruz Pinto; Pinto, A. M. P.; Simões, S.; Guedes, A.Ti6Al4V and Al2O3 were successfully vacuum brazed at 980 °C using TiCuNi filler foil. The microstructure and the chemical composition of the interface were analysed by SEM (scanning electron microscopy) and EDS (energy dispersive spectros- copy), respectively. The hardness profile across the interface and the mechanical strength of joints were assessed by Vickers microhardness tests and shear tests, respectivel...
A study on a cast steel reinforced with WC-metal matrix composite
Moreira, Aida B.; Ribeiro, Laura M. M.; Lacerda, Pedro; Pinto, A. M. P.; Vieira, Manuel F.This study seeks to investigate the local reinforcement of low carbon cast steel specimens with WC–metal matrix composites (WC–MMCs), to obtain a new material effective in competing with hard alloy steels. For this purpose, a powder compact of tungsten carbide (WC) and iron (Fe) was prepared and placed in the mold cavity before casting. The reactions that occurred with the molten steel led to the formation of t...
Influence of calcium acetate concentration in electrolyte on tribocorrosion beh...
Sousa, Luís; Mendes, Ana Rita; Pinto, A. M. P.; Toptan, Fatih; Alves, Alexandra Manuela Vieira Cruz PintoTi-based materials are widely used for dental and orthopaedic implant applications due to their adequate mechanical properties, corrosion behaviour and biocompatibility. However, these materials are biologically inert and display poor wear resistance. In one of the most studied processes that aims to overcome these drawbacks, Ti surfaces are often covered by anodic oxide films with the incorporation of bioactiv...
Production and characterization of austenitic stainless steel cast parts reinfo...
Moreira, Aida B.; Ribeiro, Laura M. M.; Lacerda, Pedro; Pinto, A. M. P.; Vieira, Manuel F.In this work, austenitic stainless steel specimens were locally reinforced with WC particles. The reinforcements were fabricated via an ex situ technique based on powder technology. Mixtures of WC, Fe, and M0101 binder were cold-pressed to obtain powder compacts. After debinding and sintering, the porous WC–Fe inserts were fixed in a mold cavity, where they reacted with liquid metal. Microstructural analysis wa...
TiO2 bioactive implant surfaces doped with specific amount of Sr modulate miner...
Costa, A.; Gemini-Piperni, S. [UNESP]; Alves, A. C.; Costa, N. A. [UNESP]; Checca, N. R.; Leite, P. E.; Rocha, L. A. [UNESP]; Pinto, A. M. P.Made available in DSpace on 2021-06-25T12:37:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01; FCT; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); One of the main problems that remain in the implant industry is poor osseointegration due to bioinertness of implants. In order to promote bioactivity, calcium (Ca), p...
TiO2 bioactive implant surfaces doped with specific amount of Sr modulate miner...
Costa, A. I.; Gemini-Piperni, S.; Alves, Alexandra Manuela Vieira Cruz Pinto; Costa, N. A.; Checca, N. R.; Leite, P. E.; Rocha, L. A.; Pinto, A. M. P.One of the main problems that remain in the implant industry is poor osseointegration due to bioinertness of implants. In order to promote bioactivity, calcium (Ca), phosphorus (P) and strontium (Sr) were incorporated into a TiO2 porous layer produced by micro-arc oxidation. Ca and P as bioactive elements are already well reported in the literature, however, the knowledge of the effect of Sr is still limited. I...
Preparation and microstructural characterization of a high-Cr white cast iron r...
Moreira, Aida B.; Ribeiro, Laura M. M.; Lacerda, Pedro; Sousa, Ricardo O.; Pinto, A. M. P.; Vieira, Manuel F.High-chromium white cast iron (WCI) specimens locally reinforced with WC–metal matrix composites were produced via an ex situ technique: powder mixtures of WC and Fe cold-pressed in a pre-form were inserted in the mold cavity before pouring the base metal. The microstructure of the resulting reinforcement is a matrix of martensite (α’) and austenite (γ) with WC particles evenly distributed and (Fe,W,Cr)<sub>6</...
Interactions between wear and corrosion on cast and sintered Ti-12Nb alloy in c...
Caha, Ihsan; Alves, Alexandra Manuela Vieira Cruz Pinto; Chirico, C.; Tsipas, S. A.; Rodrigues, I. R.; Pinto, A. M. P.; Grandini, C. R.; Rocha, L. A.This work investigates the corrosion and tribocorrosion behavior of alpha + beta Ti-12Nb alloy processed by casting and sintering, in 9 g/l NaCl solution at body temperature, and compares the results with the commercial Ti-6Al-4 V alloy. Different electrochemical techniques were used to access the corrosion behavior. Tribocorrosion behavior was studied at open circuit potential under continuous and intermittent...
Microstructural characterization of TiC–White cast-iron composites fabricated b...
Moreira, Aida B.; Sousa, Ricardo O.; Lacerda, Pedro; Ribeiro, Laura M. M.; Pinto, A. M. P.; Vieira, Manuel F.High-chromium white cast-iron specimens locally reinforced with TiC–metal matrix composites were successfully produced via an in situ technique based on combustion synthesis. Powder mixtures of Ti, Al, and graphite were prepared and compressed to fabricate green powder compacts that were inserted into the mold cavity before the casting. The heat of the molten iron causes the ignition of the combustion reaction ...
Effect of bio-functional MAO layers on the electrochemical behaviour of highly ...
Alves, Alexandra Manuela Vieira Cruz Pinto; Costa, A., I; Toptan, Fatih; Alves, J. L.; Leonor, I. B.; Ribeiro, E.; Reis, R. L.; Pinto, A. M. P.Ti foams are attractive for orthopaedic applications due to reduced Young's modulus and ability of bone ingrowth. However, poor corrosion behaviour and lack of bioactivity are yet to be overcome. In the present work, highly porous Ti samples were processed by powder metallurgy with space holder technique and bio-functionalized by micro-arc oxidation, resulting in nano/micro structured TiO2 surfaces containing b...