2相?？拷缚p的熱影響區(qū)內(nèi)的層狀γ晶具有明顯的流線特征，其方向與焊接界面熱塑性金屬的流動(dòng)方向一致。接頭的顯微硬度從母材區(qū)到焊縫區(qū)呈逐漸增加的趨勢(shì)，焊縫區(qū)顯微硬度相較于母材區(qū)增加了約1700 MPa；接頭的室溫抗拉強(qiáng)度與母材相當(dāng)，在683 MPa到717 MPa之間。焊縫區(qū)的細(xì)晶強(qiáng)化效應(yīng)是接頭強(qiáng)度較高的主要原因。;Crack-free TiAl joints were welded by linear friction welding with online stress relieving process. Microstructural examination demonstrates that the joint has a clearly identified weld zone which consists mainly of equiaxed γ grains with a few α2 phase. Lamellar grains in thermo-mechanically affected zones near the weld margin are oriented along with the flow direction of the plasticized material. The microhardness of the joint presents a global increase from the base metal to the weld interface by about 1700 MPa; the tensile strength of the joints ranges from 683 MPa to 717 MPa at ambient temperature, which is comparable to that of the base metal. The refinement strengthening contributes to enhancing the joint strength."/>