电真空用冷轧钼薄板晶粒取向与力学性能分析

Analysis of Crystallographic Orientation and Mechanical Performance of Cold-rolled Molybdenum Sheets for Vacuum Electron Devices

摘要:

利用EBSD和金相分析了电真空用0.5mm厚冷轧退火钼薄板的晶粒取向及显微组织，并探讨其与力学性能的关联性。结果表明，加工性能优异的钼薄板中晶粒取向分布相对较弱、较漫散，主要包含α线和γ线织构，其中α线织构的最大组分为旋转立方{001}<110>，并含有一定量{112}<110>；晶粒多为沿RD方向且平行轧面顺序排列的“扁云片”状；有相对较少的θ＞50°大角度晶界；这使得RD、TD及45°-RD方向的屈强比和延伸率均较高，延伸率各向异性较低，强塑性匹配良好。

Abstract:

Crystallographic orientation and microstructure of the 0.5mm thick cold-rolled annealed molybdenum sheets for vacuum electron devices were analysed by electron back-scattered diffraction (EBSD) and metallography, and their correlation with mechanical performance was discussed. The molybdenum sheets with excellent processability have some characteristics: grain orientation distribution which is relatively weaker and more diffused, mainly consists of α-fiber and γ-fiber texture. In the α-fiber texture, rotation cubic {001}<110> is the maximum component, and an amount of {112}<110> exists. Observed microstructures are mostly flat cloud-flake grains arrayed orderly along rolling direction and paralleled to rolling surface. Relatively less high-angle boundaries with θ> 50° are detected. Therefore, the Mo sheets show higher yield ratio and elongation, and weaker elongation anisotropy in RD, TD, and 45°-RD directions, i.e. excellent strength and toughness matching.