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
Yttria stabilized zirconia(YSZ)film has been screen printed and sintered on a rigid substrate.The constrained sintering caused the formation of multiple microcracks and most critically large“blister”defects.The morp...Yttria stabilized zirconia(YSZ)film has been screen printed and sintered on a rigid substrate.The constrained sintering caused the formation of multiple microcracks and most critically large“blister”defects.The morphology of such defects has been characterized by scanning electron microscopy(SEM).It was revealed that the film surface exhibits noticeable roughness.Microhardness testing revealed little variation in green density distribution.Rheological measurement,however,showed that some agglomerations are present in the YSZ ink.The existence of agglomerations in the screen printing ink in combination with debonding at the film/substrate interface is potentially the cause for the formation of blister defects.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Yttria stabilized zirconia(YSZ)film has been screen printed and sintered on a rigid substrate.The constrained sintering caused the formation of multiple microcracks and most critically large“blister”defects.The morphology of such defects has been characterized by scanning electron microscopy(SEM).It was revealed that the film surface exhibits noticeable roughness.Microhardness testing revealed little variation in green density distribution.Rheological measurement,however,showed that some agglomerations are present in the YSZ ink.The existence of agglomerations in the screen printing ink in combination with debonding at the film/substrate interface is potentially the cause for the formation of blister defects.
