The Multi layer coating of Ni60 alloy was got by multi layer laser cladding. The height of the coating was about 12mm and the wall of the coating was perpendicular to the base. The microstructure of the coating was ...The Multi layer coating of Ni60 alloy was got by multi layer laser cladding. The height of the coating was about 12mm and the wall of the coating was perpendicular to the base. The microstructure of the coating was made up of fine dendrite. The conjunction between layers was good.展开更多
By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mg-based alloys(ZM2 and ZM5) can reach about 1.0 mm.The microstructure of the substrate and the cladding zone was stud...By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mg-based alloys(ZM2 and ZM5) can reach about 1.0 mm.The microstructure of the substrate and the cladding zone was studied using optical microscope, scanning electron microscopy(SEM), X-ray diffractometry(XRD) and micro hardness analysis. It is observed that constituent of ZM5 alloy is δ+Mg 17Al 12, that of ZM2 alloy is α+MgZn+Mg 9Ce. That of cladding layer ZM2 alloy(L-ZM2) is Mg+Mg 2Zn 11+MgCe; while that of the cladding layer ZM5 alloy(L-ZM5) is Mg+Mg 32(Al, Zn) 49. The hardness of the cladding area can be increased to values above HV127. Very fine uniform microstructure and the produced new phases of nanometer/sub-micrometer order were obtained. Now, many repaired Mg-based alloy components have been passed by flying test in outside field.展开更多
The laser cladding of Ni1015 alloy on Cu substrate was prepared by a high power continuous wave CO2 laser. Its microstructure was analyzed by optical microscope （OM）, scanning electron microscope （SEM）, and X-Ray ...The laser cladding of Ni1015 alloy on Cu substrate was prepared by a high power continuous wave CO2 laser. Its microstructure was analyzed by optical microscope （OM）, scanning electron microscope （SEM）, and X-Ray diffraction （XRD）. The average microhardness of the cladding coating was Hv 280, which was almost three times of that of the Cu substrate （Hv 85）. OM and SEM observations showed that the obtained coating had a smooth and uniform surface, as well as a metallurgical combination with the Cu substrate without cracks and pores at the interface. With the addition of copper into the nickel-based alloy, the differences of thermal expansion coefficient and melting point between the interlayer and cladding were reduced, which resulted in low stresses during rapid cooling. Moreover, large amount of （Cu, Ni） solid solution formed a metallurgical bonding between the cladding coating and the substrate, which also relaxed the stresses, leading to the reduction of interfacial cracks and pores after laser cladding.展开更多
TiC/Ti composite layers were produced by laser melting the preplaced mixture of Ti and TiC powders. The results show that the microstructure, microhardness and wear resistance of the clad layer are all evaluated. The ...TiC/Ti composite layers were produced by laser melting the preplaced mixture of Ti and TiC powders. The results show that the microstructure, microhardness and wear resistance of the clad layer are all evaluated. The composite layer consists of TiC and α-Ti phases. TiC in the clad zone exists in the form of fine dendrites and Ti fills among TiC dendrites, which has a typical structure of TiC/Ti composite. The microhardness of the composite coating is significantly enhanced as high as HV_ 0.2940 as compared to HV_ 0.2345 of the substrate region. The composite layer has excellent wear resistance compared to titanium alloy.展开更多
In this study, a roll-bonded UNS N088225 alloy clad pipeline steel was investigated and developed in Baosteel. Based on the requirements of a number of potential projects, we performed a series of strict evaluations i...In this study, a roll-bonded UNS N088225 alloy clad pipeline steel was investigated and developed in Baosteel. Based on the requirements of a number of potential projects, we performed a series of strict evaluations including mechanical and corrosion tests. The results show the mechanical properties and corrosion resistance of this clad steel to be excellent and to meet the requirements of all the design parameters.展开更多
文摘The Multi layer coating of Ni60 alloy was got by multi layer laser cladding. The height of the coating was about 12mm and the wall of the coating was perpendicular to the base. The microstructure of the coating was made up of fine dendrite. The conjunction between layers was good.
文摘By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mg-based alloys(ZM2 and ZM5) can reach about 1.0 mm.The microstructure of the substrate and the cladding zone was studied using optical microscope, scanning electron microscopy(SEM), X-ray diffractometry(XRD) and micro hardness analysis. It is observed that constituent of ZM5 alloy is δ+Mg 17Al 12, that of ZM2 alloy is α+MgZn+Mg 9Ce. That of cladding layer ZM2 alloy(L-ZM2) is Mg+Mg 2Zn 11+MgCe; while that of the cladding layer ZM5 alloy(L-ZM5) is Mg+Mg 32(Al, Zn) 49. The hardness of the cladding area can be increased to values above HV127. Very fine uniform microstructure and the produced new phases of nanometer/sub-micrometer order were obtained. Now, many repaired Mg-based alloy components have been passed by flying test in outside field.
基金This research was financially supported by the National Natural Science Foundation of China (No.50574020) and Shanghai BaoSteel Group Co.
文摘The laser cladding of Ni1015 alloy on Cu substrate was prepared by a high power continuous wave CO2 laser. Its microstructure was analyzed by optical microscope （OM）, scanning electron microscope （SEM）, and X-Ray diffraction （XRD）. The average microhardness of the cladding coating was Hv 280, which was almost three times of that of the Cu substrate （Hv 85）. OM and SEM observations showed that the obtained coating had a smooth and uniform surface, as well as a metallurgical combination with the Cu substrate without cracks and pores at the interface. With the addition of copper into the nickel-based alloy, the differences of thermal expansion coefficient and melting point between the interlayer and cladding were reduced, which resulted in low stresses during rapid cooling. Moreover, large amount of （Cu, Ni） solid solution formed a metallurgical bonding between the cladding coating and the substrate, which also relaxed the stresses, leading to the reduction of interfacial cracks and pores after laser cladding.
文摘TiC/Ti composite layers were produced by laser melting the preplaced mixture of Ti and TiC powders. The results show that the microstructure, microhardness and wear resistance of the clad layer are all evaluated. The composite layer consists of TiC and α-Ti phases. TiC in the clad zone exists in the form of fine dendrites and Ti fills among TiC dendrites, which has a typical structure of TiC/Ti composite. The microhardness of the composite coating is significantly enhanced as high as HV_ 0.2940 as compared to HV_ 0.2345 of the substrate region. The composite layer has excellent wear resistance compared to titanium alloy.
基金partially sponsored by Shanghai Pujiang Program(No.16PJ1430200)
文摘In this study, a roll-bonded UNS N088225 alloy clad pipeline steel was investigated and developed in Baosteel. Based on the requirements of a number of potential projects, we performed a series of strict evaluations including mechanical and corrosion tests. The results show the mechanical properties and corrosion resistance of this clad steel to be excellent and to meet the requirements of all the design parameters.
