热机械处理对Ti_3Al基合金板条组织形貌及室温拉伸性能的影响

Effect of Thermomechanical Processing on the Morphologies and Room Temperature Tensile Properties of Lath Microstructure in Ti 3Al Based Alloy

研究了热机械处理（ＴＭＰ）对Ｔｉ３Ａｌ基合金Ｔｉ－２４Ａｌ－１４Ｎｂ－３Ｖ（原子分数，％）板条组织的形貌及室温拉伸性能的影响。通过ＴＭＰ可获得各种各样的板条组织。Ｔｉ－２４Ａｌ－１４Ｎｂ－３Ｖ板条组织的最高断裂强度可达１２２５ＭＰａ，最大伸长率达８．５％。对板条形貌与室温拉伸性能的关系进行了分析，用ＳＥＭ观察了室温拉伸过程中的裂纹扩展情况。经ＴＥＭ观察发现，在缓冷样品中板条周边存在着一种α２＋Ο相的复合结构。

The effect of thermomechanical processing (TMP) on the morphologies and room temperature tensile properties of lath microstructure in Ti 3Al based alloy, Ti 24Al 14Nb 3V(at%), has been studied. A series of morphologies of lath microstructure can be attained by TMP. The maximum ultimate strength of 1 225 MPa and the maximum elongation of 8.5 % have been obtained for the lath microstructure in Ti 24Al 14Nb 3V. The relationship between the morphologies and RT tensile properties was analysed and the fracture crack extension was observed by SEM during RT tension. The α 2+ Ο combined structure was found by TEM in the peripheries of lathes for the slow cooled specimens.