【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.更多还原

【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]_αdirection 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-likeβ-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.更多还原