Microstructure and texture evolution in Ti-6Al-4V alloy under different hammer forging processes
-
摘要: 利用掃描電鏡和背散射衍射技術研究了Ti-6Al-4V合金在不同錘鍛變形方式下的組織與取向變化.結果顯示:隨著鐓拔變形次數的增加,Ti-6Al-4V合金中α相及β相組織均趨于均勻,而且兩相的取向聚集越不明顯;進一步熱處理后,鍛造過程中形變儲存能得到釋放,在釋放過程中兩相也會發生一定的傾轉,軸向三次鐓拔或者換向三次鐓拔對組織均勻性改善明顯.綜合分析發現,密排六方結構的α相的取向分布對變形方式較敏感:原始棒材以及一次鐓拔時,合金中α相的取向{0001}基面織構占了很大部分;隨著鐓拔次數增多,形變能增加,雖然{0001}基面滑移被抑制,但是{1010}、{1120}等柱面滑移以及{0111}、{1123}等錐面滑移得以開動,大幅地增加了取向的種類,進而降低了取向的集中性,使得取向更趨均勻化.Abstract: Microstructure and texture evolution in Ti-6Al-4V alloy under different hammer forging processes were investigated by electron backscattered diffraction and scanning electron microscopy. The results showed that the inicrostructure became more and more uniform along with the frequency of forging, and the directionality turned more and more invisible; after heat treatment, the distribu-tion uniformity of α and β phases and the micro-texture were both increased to somewhat extent because of the release of deformation energy and the tilting of α and β phases, especially highlighted in the forging modes of uniaxial 3 times and cross upsetting and stretching 3 times. As for the texture distribution of this alloy, the close-packed hexagonal structured α phase was more sensitive to hot working modes than the body centered α phase. For raw materials and one-time axial upsetting and stretching, the texture of α phase mainly consisted of the {0001 } basal texture; with the increase of frequency and deformation energy, the {1010} and {1120} prismatic slip and the {1011} and {1212} pyramidal slip were strengthened, accordingly inducing the more uniform of orientation because of the texture components and the dispersion of texture distribution.
-
Key words:
- titanium alloys /
- forging /
- deformation modes /
- microstructure /
- orientation
-

計量
- 文章訪問數: 233
- HTML全文瀏覽量: 45
- PDF下載量: 11
- 被引次數: 0