The composite coatings were formed by plasma cladding Fe-based alloy（Fe-Cr-B-Si） added 10% , 30% and 50% （mass fraction） nickel-clad WC respectively on Q235 steel. The microstructure evolution and microhardness of...The composite coatings were formed by plasma cladding Fe-based alloy（Fe-Cr-B-Si） added 10% , 30% and 50% （mass fraction） nickel-clad WC respectively on Q235 steel. The microstructure evolution and microhardness of the coatings were investigated. The WC particles were completely melted into the composites coating when 10% WC was added, however, when 30% or 50% WC was added, only part of them could be melted in the coatings. Two significantly different solidification microstructures were found. When WC content is 10% or 30%, the microstructure is mainly dendrites and inter- dendrite eutectics, while when the content of WC reaches 50% , it becomes remained WC particles, Fe3 W3 C carbide faceted dendrite and eutectics hypereutectic structure. The microhardness of these three coatings reaches 560- 600, 650 -810 and 920 - 1 100 HVo2 respectively, and is improved with the increasing of WC content.展开更多
The convection patterns were observed in laser cladding layer of FeCrSiB alloy.Laser beam symmetry, dilution of cladding layer from substrate,etc.With relation to con- vection patterns have been investigated.Macro-seg...The convection patterns were observed in laser cladding layer of FeCrSiB alloy.Laser beam symmetry, dilution of cladding layer from substrate,etc.With relation to con- vection patterns have been investigated.Macro-segregation and macroalloying in the cladding layer were found to be resulted from convection.The dilution rates of substrate materials into cladding layer are directly influential in microstructure and performace of the cladding.Ideal laser cladding conditions require that there is a minimum of dilution.展开更多
文摘The composite coatings were formed by plasma cladding Fe-based alloy（Fe-Cr-B-Si） added 10% , 30% and 50% （mass fraction） nickel-clad WC respectively on Q235 steel. The microstructure evolution and microhardness of the coatings were investigated. The WC particles were completely melted into the composites coating when 10% WC was added, however, when 30% or 50% WC was added, only part of them could be melted in the coatings. Two significantly different solidification microstructures were found. When WC content is 10% or 30%, the microstructure is mainly dendrites and inter- dendrite eutectics, while when the content of WC reaches 50% , it becomes remained WC particles, Fe3 W3 C carbide faceted dendrite and eutectics hypereutectic structure. The microhardness of these three coatings reaches 560- 600, 650 -810 and 920 - 1 100 HVo2 respectively, and is improved with the increasing of WC content.
文摘The convection patterns were observed in laser cladding layer of FeCrSiB alloy.Laser beam symmetry, dilution of cladding layer from substrate,etc.With relation to con- vection patterns have been investigated.Macro-segregation and macroalloying in the cladding layer were found to be resulted from convection.The dilution rates of substrate materials into cladding layer are directly influential in microstructure and performace of the cladding.Ideal laser cladding conditions require that there is a minimum of dilution.
