Microstructure Characteristics and Formation Mechanism of Laser Clad High Temperature Self Lubrication Wear Resistant Composite Coatings on γ-TiAl Intermetallic Alloy
In order to obtain high performance elevated temperature self lubrication anti-wear composite coatings on TiAl alloy, a novel Ni-P electroless plating approach was adopted to encapsulate the as-received CaF2 in the preparation of precursor NiCr-Cr3C2-CaF2 mixed powders with an aim to decrease its mass loss and increase its compatibility with the metal matrix during a Nd: YAG laser cladding. Phases, microstructures, compositions, and wear properties of the laser clad composite coatings were studied. It showed that the coating had a unique microstructure consisting of primary dendrites TiC and block Al4C3 carbides reinforcement as well as fine isolated spherical CaF2 solid lubrication particulates uniformly dispersed in the NiCrAlTi (γ) matrix. The good comprehensive tribological properties of the composite coatings were attributed to the presence of very high hardness carbides TiC and Al4C3 dispersed in the ductile and tough NiCrAITi (γ) matrix, and the valuable friction-reducing abilities was suggested to the Ni-P electroless plating and the attendant reduction of mass loss of CaF2 and the increasing of its wettability with the NiCrAlTi (γ) matrix during the laser cladding process.
Microstructure Laser processing High temperature wear resistant composite coating Solid lubrication Ni-P electroless plating γ-TiAl intermetallic alloy
LIU Xiu-Bo SHI Shi-Hong FU Ge-Yan WANG Ming-Di
School of Mechanical & Electrical Engineering,178 Ganjiang East Road,Soochow University,Suzhou 215021,China
国际会议
The Fourth Asian Conference on Heat Treatment and Surface Engineering(第四届亚洲热处理及表面工程大会)
北京
英文
529-533
2009-10-27（万方平台首次上网日期，不代表论文的发表时间）