用相变晶体学指导Mg-Sn-Mn合金优化设计

来源期刊：金属学报2011年第1期

论文作者：石章智 张文征

文章页码：41 - 46

关键词：镁合金设计； 相变晶体学； 析出相形貌； 位向关系

Key words：magnesium alloy design； crystallography of phase transformation； morphology of precipitates； orientation relationship

摘    要：以相变晶体学为主要原则对Mg-Sn-X合金进行优化设计.在对现有镁合金系统充分调研的基础上,根据Mg基体与析出相的相变晶体学匹配关系,提出2条相变晶体学判据来判断可能沿Mg基体[0001]_α方向择优生长的析出相.根据这2条相变晶体学判据结合相图分析推测在Mg-Sn-Mn系统中可能得到沿Mg基体[0001]_α方向择优生长的β-Mn析出相.对Mg-7.5Sn-2.2Mn(质量分数,%)合金时效组织的TEM研究证实了上述判断.研究结果表明,β-Mn析出相呈棒状,长轴沿Mg基体[000i]_α方向,它与Mg基体的位向关系(OR)是:[0001]_α∥[211]_β-Mn,[0110]_α∥[011]_β-Mn,[2110]_α∥[111]_β-Mn.

Abstract: Crystallography of phase transformation is used as the main principal to guide MgSn -X alloy design. Based on a comprehensive literature survey two criteria of crystallography of phase transformation are given to select the precipitate probably growing along [0001]_α direction of Mg matrix. Combined with available data of phase diagram, we deduce thatβ-Mn in Mg-Sn-Mn system is a hopeful candidate. TEM study on the specimen of Mg-7.5Sn-2.2Mn (mass fraction, %) alloy confirms that rod-like β-Mn precipitates grow along [0001]_α,and their orientation relationship (OR) with Mg matrix is [0001]_α//[2Tl]_β-Mn, [0110]_α//[011]_β-Mn,[2110]_α//[111]_β-Mn.