【摘要】 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。更多还原

【Abstract】 To improve fracture toughness of MoSi₂ at room temperature,SiC_p-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（K_IC）,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 SiC_p-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·m1/2.Furthermore,mechanism of hardening and toughening is discussed respectively.更多还原