【摘要】 利用W,Mo,Si粉末燃烧合成复合发热元件原料,制备WSi2/MoSi2复合发热元件。通过显微结构和力学性能、物理性能的测试分析表明:复合发热元件显微组织细小、分布较均匀,结晶相主要是以固溶形式的(WxMoy)Si2以及少量(WxMoy)5Si3相存在(其中x+y=1),玻璃相是以SiO2和Al2O3为主,并含有少量的Na,Mg,K,Ca等金属氧化物;断口晶粒细小,主要表现为沿晶断裂,抗弯强度和显微硬度较高;复合发热元件电阻率与MoSi2发热元件相近,没有老化现象;烧损温度高于MoSi2发热元件80℃,热膨胀系数低于MoSi2发热元件,热稳定性较好;复合发热元件表面膜是一种复合硅氧膜,成膜质量较好。更多还原

【Abstract】 The material of composite heat element was synthesized by the combustion of W, Mo and Si powder to prepare the WSi2/MoSi2 composite heat element by sintering processing. The analysis of microstructure, mechanical property and physical property showed that the microstructure of composite heat element was fine and homogeneous. It was confirmed that the crystalline phases were (WxMoy)Si2 mainly in solid solution and a few of (WxMoy)5Si3 (x+y=1). Most glass phases were SiO2 and Al2O3, and some metallic oxides of Na, Mg, K, and Ca. Fine-grained and inter crystalline fracture were observed for the composite heat element with high bending strength and micro hardness and similar electrical resistivity to MoSi2 heat element, and no aging phenomena. The burn temperature was 80℃, higher than MoSi2 heat element. The thermal expansion coefficient of composite heat element was lower than MoSi2 heat element with a good thermal stability. The surface film was composed of silicon and oxygen composite film with good quality for the composite heat element.更多还原