钛合金β→α相变的变体选择

Abstract

β→α转变是钛合金中最基本和最重要的一种相变，两相之间存在严格的Burgers取向关系，即(0001)α//{110}β和20>α//β，这种关系决定了在一个β晶粒内可能会出现12个α相变体。在各种类型的钛合金中，均会出现在一个β晶粒内只有少数几个取向的α相能够存在的现象，即发生变体选择，其对强度、塑性、疲劳等力学性能的负面影响逐步被关注，抑制其发生将是进一步提高钛合金性能的潜在方法之一。本文结合作者的研究工作，介绍了钛合金中β→α转变时发生变体选择的本质、成因以及对合金力学性能的影响等方面的研究现状，并分析了该研究方向目前存在的问题和今后的研究重点。 β→α transformation is the most essential phase transition in titanium alloys. The α phase formed in the β matrix is oriented according to the so-called Burgers orientation relationship, viz. (0001)α//{110}β and 20>α//β. Because of the symmetry of the two crystals, 12 α va-riants can form in a β grain theoretically. Variant selection can take place in almost all kinds of ti-tanium alloys and decline the strength, plasticity and fatigue resistance, which have been attended by the researchers gradually. To control the occurrence of variant selection will be one of the po-tential methods to improve the properties of titanium alloys. In this paper, by integrating our re-search work, the progress in research of variant selection of β→α phase transformation in titanium alloys is briefly reviewed from aspects of the substance and the reason of variant selection, and its influence on the mechanical properties. The problems at present study and the research directions in the future are also analyzed.