用相变晶体学指导Mg-Sn-Mn合金优化设计

Crystallography of phase transformation is used as the main principal to guide Mg- Sn-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 that β-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//(211)β−Mn ,( 0110)α//(011)β−Mn ,( 2110)α//(111)β−Mn.