铝合金薄板尖边缘缺口试样的机械加工方法及缺口敏感性测试

介绍高强度铝合金薄板的尖边缘缺口拉伸试样的机械加工方法，用该方法制备的仿美７０７５、美制７０７５、国产ＬＣ４、ＬＣ９、ＬＹ１２、ＬＢ７３３等６种铝合金１６种热处理状态下的ＥＮ试样，其内率半径Ｒ满足了ＡＳＴＭＥ３３８－６８标准方法中Ｒｍａｘ０．０１８毫米的要求，并且达到Ｒ＜０．０１０毫米的特高精度。同时，还对仿美７０７５、美制７０７５、国产ＬＣ４的６种热处理状态下的缺口敏感性和宏观断口、以及选择仿美７０７５、ＬＹ１２对扫描断口形态进行了研究。

Machining Method for the Samples of Al-alloy Thin Sheet with Pointed Notches on the Edges and the Test of the Sensibility of Notches

The machining method for the elongation sample of high-strength Al-alloy thin sheet with pointed notches on the edges is introduced. The EN samples of six Al alloys, i.e. the imitated U.S. 7075, U. S. 7075, domestic LC4, LC9, LY12, and LB733 are prepared by this method under sixteen different conditions of heat treatments. The radius of curvature R satisfies the requirement of Rmax 0.018 mm in ASTM E338-68, and reaches the extra high precision of R0.010 mm. Moreover, the sensibility of notches of imitated U.S. 7075, U.S. 7075 and domestic LC4 under 6 conditions of heat treatment and macroscopic fractures, as well as the forms of scanning fractures of imitated U.S.7075 and LY12 are studied.