TA17钛合金板材对接焊缝显微组织表征研究

利用电子背散射衍射（EBSD）取向成像技术,对TA17钛合金板材对接焊缝的显微组织、晶界特征和晶体学取向进行表征研究。结果表明其母材呈典型的轧制变形组织,且由α相和少量晶间分布的β相组成,大部分为小角度晶界,为基面织构。热影响区晶粒呈梯度长大分布。在焊接热传导下,热影响区晶粒得到回复和长大,大角度晶界逐渐增多。其织构继承了母材织构的特点,只是织构密度有所减弱。熔区为粗大的α＇马氏体相交织成的网篮状组织,大部分为大角度晶界,织构比较漫散。

Microstructure analysis on butt welding line of TA17 titanium alloy plates

The grain structure,grain boundary characterization and texture of butt welding line were analyzed by EBSD technic on TA17 titanium alloy plates.The results show that the matrix has typical rolling state microstructure composed with α phase as well as a few β phases on grain boundaries.A lot of low angle grain boundaries can be observed on the matrix with basal texture as the main texture type.Characteristic of gradual growth is presented for grains on heat impacting area.Grains at heat impacting area near matrix will recover and grow up under the effect of heat exchange of welding.High angle grain boundary will also increase at this area.Texture at heat impacting area inherits the texture characteristic of matrix with the low density.The melting zone has coarsened basket structure composed by α′ martensite mainly with high angle grain boundary and desultory texture.