热等静压处理对Ti(C,N)基金属陶瓷组织和性能的影响

用真空预烧及热等静压处理制备了Ti(C,N)基金属陶瓷。用SEM、TEM、EDX等研究了经热等静压处理后金属陶瓷的显微组织特点。同时研究了真空预烧温度对Ti(C,N)基金属陶瓷组织和性能的影响规律。结果表明:经热等静压处理后,材料仍然具有芯-壳结构,只是在Rim相中靠近硬质相那一侧不同程度地出现白色细小的析出物。热等静压过程中液相颗粒被重新析出的Rim相包裹是白色析出物出现的原因。当热等静压处理温度高达1450℃时,白色析出物会明显增多,大量白色析出物的出现使材料的机械性能降低。当真空预烧温度为1410℃时,经热等静压处理后,使材料的组织均匀,晶粒显著细化,且白色析出物很少,因而使材料的机械性能得到较大的提高。

Effect of HIP on the Microstructure and Mechanical Properties of Ti(C,N)-based Ceramet

Ti(C,N)-based ceramets were fabricated by vacuum pre-sintered and treated by hot isostatic pressing. The characteristics of the microstructures of the cermets were studied by SEM, TEM, EDX and et al. The effects of pre-sintering temperature on the microstructure and mechanical properties were also researched. The experimental results show that the cermets treated by HIP contained many ceramic grains with the typical "core-rim" structures. However, some white small grains precipitated in the inner rim around the core, which resulted from the phenomenon that the liquid metal drops were enwrapped by the reprecipitated rim phase. When the HIP temperature reached 1450℃, the amount of the white precipitates increased greatly, which resulted in the reduction of mechanical properties of the ceramets. When the pre-sintering temperature was 1410℃, HIP treatment not only made the microstructure of the cermets become homogeneous and refined the grains greatly, but also reduced the amount of the white precipitates. As a result, the mechanical properties of the cermets were improved.