Coatings of metal matrix composites(Cu?WC)were fabricated by solid-state sintering.WC reinforcing particles indifferent quantities from5%up to30%(volume fraction)were mixed with Cu particles.After mixing,the powders w...Coatings of metal matrix composites(Cu?WC)were fabricated by solid-state sintering.WC reinforcing particles indifferent quantities from5%up to30%(volume fraction)were mixed with Cu particles.After mixing,the powders were poured ontothe surface of copper substrates.Sintering was carried out at1000°C under a reducing atmosphere in a vertical dilatometer.Sinteringkinetics was affected by both rigid substrates and WC particles which retarded the radial and axial densification of powders.However,the coatings were strongly attached to the substrate,and WC particles were randomly distributed within the matrix.The addition ofthe reinforcing particles enhanced the microhardness and reduced the volume loss in wear tests to1/17compared to the unreinforcedsample.The predominant wear mechanism was identified as abrasion at a load of5N.20%WC(volume fraction)reinforcingparticles led to the maximum values of properties for the composite coating.展开更多
Application of laser shock processing （LSP） on 6061-T6 aluminum was made in order to evaluate its response to the erosive wear by silica sand. Impact angles of 15° , 30° , 60° and 90° were tes...Application of laser shock processing （LSP） on 6061-T6 aluminum was made in order to evaluate its response to the erosive wear by silica sand. Impact angles of 15° , 30° , 60° and 90° were tested, two particle speeds （37 and 58 m/s） and two LSP irradiation conditions were used. Erosion marks were characterized by 3D profilometry and SEM analysis was conducted to identify the erosion mechanisms for each tested angle. The results showed a maximum erosive wear at low impact angles （ductile type behavior）. Erosion strength and the erosion mechanisms were not affected by the application of LSP and they were attributed to the high strain rate of the erosion phenomena. A few differences encountered on the erosion plots were explained on the basis of the surface roughness left by the LSP process. The maximum mass loss and the maximum erosion penetration happened in different impact angles （15° and 30° , respectively）. Finally, a well-defined erosion mechanism transition was observed, from cutting action at low impact angle, to crater formation at 90° of incidence.展开更多
The corrosion and tribocorrosion behavior of Ti6Al4V/xTiN(x=0,5,10 and 15,vol.%)composites fabricated by solid-state sintering and their relationship with the microstructure and microhardness were investigated.Simulat...The corrosion and tribocorrosion behavior of Ti6Al4V/xTiN(x=0,5,10 and 15,vol.%)composites fabricated by solid-state sintering and their relationship with the microstructure and microhardness were investigated.Simulated body conditions such as a temperature of 37℃ and a simulated body fluid were used.The main results demonstrated a microstructural change caused by theα-Ti stabilization due to solid-solution of nitrogen(N)into the titanium(Ti)lattice,producing a maximum hardening effect up to 109%for the Ti64 matrix by using 15 vol.%TiN.Corrosion potentials of composites changed to more noble values with the TiN particle addition,while corrosion current density of samples increased as an effect of the remaining porosity,decreasing the corrosion resistance of materials.However,changes to a less passive behavior were observed for samples with 15 vol.%TiN.The non-passive behavior of composites resulted in the reduction of the potential drops during rubbing in tribocorrosion tests.Besides,an improvement of up to 88%of the wear rate of composites was seen from the solid-solution hardening.The results allowed to understand the relationship between composition and sintering parameters with the improved tribocorrosion performance of materials.展开更多
基金CONACy T through the project CB-167111the Scientific Research Department of the UMSNH and the Guadalajara University for the financial support and the facilities to develop this study
文摘Coatings of metal matrix composites(Cu?WC)were fabricated by solid-state sintering.WC reinforcing particles indifferent quantities from5%up to30%(volume fraction)were mixed with Cu particles.After mixing,the powders were poured ontothe surface of copper substrates.Sintering was carried out at1000°C under a reducing atmosphere in a vertical dilatometer.Sinteringkinetics was affected by both rigid substrates and WC particles which retarded the radial and axial densification of powders.However,the coatings were strongly attached to the substrate,and WC particles were randomly distributed within the matrix.The addition ofthe reinforcing particles enhanced the microhardness and reduced the volume loss in wear tests to1/17compared to the unreinforcedsample.The predominant wear mechanism was identified as abrasion at a load of5N.20%WC(volume fraction)reinforcingparticles led to the maximum values of properties for the composite coating.
文摘Application of laser shock processing （LSP） on 6061-T6 aluminum was made in order to evaluate its response to the erosive wear by silica sand. Impact angles of 15° , 30° , 60° and 90° were tested, two particle speeds （37 and 58 m/s） and two LSP irradiation conditions were used. Erosion marks were characterized by 3D profilometry and SEM analysis was conducted to identify the erosion mechanisms for each tested angle. The results showed a maximum erosive wear at low impact angles （ductile type behavior）. Erosion strength and the erosion mechanisms were not affected by the application of LSP and they were attributed to the high strain rate of the erosion phenomena. A few differences encountered on the erosion plots were explained on the basis of the surface roughness left by the LSP process. The maximum mass loss and the maximum erosion penetration happened in different impact angles （15° and 30° , respectively）. Finally, a well-defined erosion mechanism transition was observed, from cutting action at low impact angle, to crater formation at 90° of incidence.
基金the University of Guadalajara for the support during the development of this researchsupported by CONACyT, México [CB-2017-2018-11813]by the State Council of Science and Technology of Jalisco (COECYTJAL), México [8205-2019]
文摘The corrosion and tribocorrosion behavior of Ti6Al4V/xTiN(x=0,5,10 and 15,vol.%)composites fabricated by solid-state sintering and their relationship with the microstructure and microhardness were investigated.Simulated body conditions such as a temperature of 37℃ and a simulated body fluid were used.The main results demonstrated a microstructural change caused by theα-Ti stabilization due to solid-solution of nitrogen(N)into the titanium(Ti)lattice,producing a maximum hardening effect up to 109%for the Ti64 matrix by using 15 vol.%TiN.Corrosion potentials of composites changed to more noble values with the TiN particle addition,while corrosion current density of samples increased as an effect of the remaining porosity,decreasing the corrosion resistance of materials.However,changes to a less passive behavior were observed for samples with 15 vol.%TiN.The non-passive behavior of composites resulted in the reduction of the potential drops during rubbing in tribocorrosion tests.Besides,an improvement of up to 88%of the wear rate of composites was seen from the solid-solution hardening.The results allowed to understand the relationship between composition and sintering parameters with the improved tribocorrosion performance of materials.
