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采用非均相沉淀-热还原法制备Ni/Ti(C,N)包覆粉,并用该包覆粉经真空烧结制得金属陶瓷。利用扫描电镜、电子能谱、X-射线衍射等手段研究包覆粉的结构形貌及烧结后的微观组织与性能。结果表明:非均相沉淀过程中,非晶态的NiCO3·2Ni(OH)2·2H2O在Ti(C,N)颗粒表面成核并生长;经热还原过程后,NiCO3·2Ni(OH)2·2H2O分解并完全还原成Ni,Ni的平均晶粒尺寸约为50nm;采用包覆粉为原料制备金属陶瓷,有效改善了硬质相和粘结相的分布均匀性,但包覆粉烧结过程中存在晶粒长大现象;金属陶瓷的相成分为纯净的Ti(C,N)与Ni两相;金属陶瓷的综合性能相对于传统工艺制得的金属陶瓷有一定提高。
The Ni / Ti (C, N) coating powder was prepared by heterogeneous precipitation-thermal reduction method and the cermet was vacuum-sintered with the coating powder. The microstructure and properties of the coated powders were investigated by scanning electron microscopy, electron spectroscopy and X-ray diffraction. The results show that amorphous NiCO3 · 2Ni (OH) 2 · 2H2O nucleates and grows on the surface of Ti (C, N) particles during the heterogeneous precipitation process. After the thermal reduction process, NiCO3 · 2Ni (OH) 2 2H2O decomposition and complete reduction to Ni, the average grain size of Ni is about 50nm; using coated powder as raw material to prepare cermet, which effectively improves the uniformity of the distribution of hard phase and binder phase, but the coating powder sintering process In the presence of grain growth phenomenon; the phase composition of cermets pure Ti (C, N) and Ni two phases; the overall performance of cermets relative to the traditional process of cermets have a certain increase.