摘要
激光熔覆Ni-Cr-B-Si-C合金涂层组织由块状CrB型硼碳化物,树枝状Cr7C3型碳化物,胞枝状γ-Ni固溶体以及共晶产物组成。依局部成份条件,形成γ-Ni+M23C6共晶和γ-Ni+镍硼化物共晶。熔覆过程的非平衡性质导致γ-Ni/Ni3B稳定凝固和γ-Ni/Ni2B亚稳定凝固并存。受快速凝固引起的热应力所致在Cr7C3和M23C6中发生高密度孪生。此外,涂层中存在非晶相,由非晶相包围的γ-Ni固溶体形成调制结构。
The microstructure of laser clad Ni Cr B Si C alloy is composed of blocky CrB type chromium carbon borides , Cr 7C 3 type chromium boron carbides, cellular dendritic γ Ni solid solution and various eutectic products. Either an eutectic of γ Ni+M 23 C 6 or an eutectic of γ Ni +nickle borides forms depending on the local composition. γ Ni/Ni 3B stable solidification and γ Ni/Ni 2B metastable solidification take place at the same time because of the rapid solidification involved in the laser cladding. Both Cr 7C 3 and M 23 C 6 contain a high density of twins resulted from stress associated with rapid solidification. In addition, an amorphous phase was found, the γ Ni surrounded by the amorphous phase exhibited a tweed contrast, suggestiv of a modulated structure.
出处
《中国激光》
EI
CAS
CSCD
北大核心
1999年第4期372-378,共7页
Chinese Journal of Lasers
基金
金属精密热加工国防科技重点实验室资助项目
