SiC_p-WSi_2/MoSi_2复合材料的室温力学性能

Room-temperature Mechanical Properties of SiC_p-WSi_2/MoSi_2 Composites

为了提高MoSi2的室温断裂韧性,将Si、Mo、W和C四种粉末混合后通过"原位反应热压"一次热压工艺制备了两种不同体积配比的SiCp-WSi2/MoSi2复合材料试样,测定了复合材料试样和纯MoSi2试样的室温断裂韧性(KIC)与显微硬度(HV);采用X射线衍射(XRD)、扫描电镜(SEM)等方法研究了该工艺下试样的结构、组织以及断口形貌与断裂韧性间的相互关系。结果表明,SiC的复合化和W元素的合金化能使SiCp-WSi2/MoSi2复合材料晶粒细化,硬度、室温断裂韧性比纯MoSi2明显提高,断裂韧性最高值达5.88MPa·m1/2。并对复合材料的硬化、韧化机理分别进行了分析。

To improve fracture toughness of MoSi2 at room temperature, SiCp-WSi2/MoSi2 specimens with different volume fraction of WSi2 and SiC particles were fabricated by means of in-situ reaction and hot press sintering after mixing the pure powder of Si, Mo, W and C. Room-temperature fracture toughness （Klc）, micro-hardness （HV） of composites and pure MoSi2 were measured. The compositions, microstructures of specimens and relations between fracture surfaces and fracture toughness were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, etc. Results show that SiC particles and alloying W refine grains of SiCp-WSi2/MoSi2, the hardness, room temperature fracture toughness of composites are significantly higher than those of pure MoSi2, fracture toughness of composite is up to 5. 88MPa·m^1/2. Furthermore, mechanism of hardening and toughening is discussed respectively.