硅化物-镍铁合金/碳化钛金属陶瓷的制备、组织结构与性能

研制了以熔融合金惰性气体雾化法制备的含有大量硅化物的镍铁合金粉末为烧结粘结相的硅化物-镍铁合金／碳化钛金属陶瓷。用SEM，EDS，XRD和热重天平等测试分析了金属陶瓷的组织结构与性能。结果表明：这种硅化物-镍铁合金／碳化钛金属陶瓷具有核／环形边缘结构，硅化物-镍铁合金对碳化钛粒子有较好的润湿烧结作用。研制的金属陶瓷的抗弯强度在1000～1200MPa，硬度HRA为80～90。由于合金中含有较高的对氧有较强亲和力的元素硅，在氧化过程中形成SiO2以及一系列复合氧化物构成的致密氧化膜，使合金具有高的抗高温氧化性能。

PREPARATION, MICROSTRUCTURE AND PROPERTIES OF SILICIDENiFe ALLOY/TiC CERMET

A new type of silicideNiFe alloy/TiC cermet, in which the silicideNiFe alloy powder was prepared by means of atomization of melted alloy and was used as sintered-binder, has been developed. The microstructures and properties of this cermet were investigated with SEM, EDS, XRD and hot-weight balance etc. The results indicated that the microstructure of the developed silicideNiFe alloy/TiC cermet shows a typical core/rim structure. During liquid-phase sintering the silicideNiFe alloy moistened the TiC particle and the surface of TiC particle was partially dissolved, then the core/rim structure formed through dissolutionprecipitation process. The bend strength of researched silicideNiFe alloy/TiC cermets is 1 000- 1 200 MPa. The hardness H R A of that cermets is 80-90. Because the alloy contained more Si and Cr, during oxidation at high temperature the SiO 2, Cr 2O 3 and several composite oxide dense layer formed on the surface of that cermet specimens, so that the silicideNiFe alloy/TiC cermet possess high resistance to high temperature oxidation.