CHEN Chuanzhong ¹, YU Huijun ¹, WANG Wenzhong ², ZHANG Shujuan ³, LEI Tingquan ⁴, YU Jiahong ⁴

（1.Shandong University of Technology; 2.Qingdao Workers University; 3.Jinan Mechanical College of Staff and Workers; 4.Harbin Institute of Technology）

Abstract: The microstructure of subsonic speed flame spraying WC／Ni metal－ceramic coating has been studied by means of Xray ‚scanning electron microscopy‚transmitting electron microscopy and selected area electronic diffraction techniques etc．The results show that the WC is decomposed since the WC／Ni particle is melting or half－melting at the higher spraying temperature ‚besides the WC of hexagonal structure‚a small amount ofα－W₂C which has close－packed hexagonal structure is formed during solidifying；a certain amount of M₆C and Ni₃C as well as a small amount of M₆C＋γ－Ni based solid solution eutectic is formed at inter－melting zone of Ni and WC‚M₆C has complex face central cubic structure while Ni₃C has orthogonal structure．

Keywords: subsonic speed flame spraying‚WC／Ni metal－ceramic‚microstructure