摘要：本文是以Al-Ti中間合金為研究對象，對其進行等通道變形（ECAP），研究不同道次變形對Al-Ti顯微組織，電導率，顯微硬度，以及作為細化劑對鋁組織細化效果與性能的影響。研究結果表明：Al-Ti中間合金經ECAP劇烈塑性變形，細長針狀Al3Ti相逐漸破碎、細化，并且均勻分布于鋁基體上。Al-Ti中間合金ECAP變形后，電導率由鑄態的33.62%IACS變為1道次后的27.93%IACS，2道次后的24.83% IACS，3道次后的23.45%IACS，電導率呈現為先降低而后平穩的趨勢。顯微硬度值也有顯著增加，由鑄態的40.1Hv變為1道次后的43.04Hv，2道次后的45.74Hv，3道次后的47.14Hv。添加ECAP變形Al-Ti中間合金到鋁熔體中，可以釋放細小的形核粒子，這些粒子促進了細小等軸晶的形成，使鑄態鋁中的柱狀晶區減小，等軸晶區擴大且晶粒更加細小。因此，ECAP變形Al-Ti中間合金細化劑在工業鋁合金組織細化方面有很大的應用潛力。

關鍵詞：Al-Ti中間合金；ECAP變形；電導率；顯微硬度；顯微組織；細化效果

Abstract:Al-Ti Master alloys was subjected to equal channel angular pressing (ECAP) investigating microstructure,electrical conductivity，micro-hardness and refining efficiency of different passes. The results show that Al-Ti samples were subjected to severe plastic deformation by using the ECAP technique, Al3Ti phase on the cast gradually deforms and breaks, at last, the phase evenly distributes on the Al matrix.It is testified that the electrical conductivity is varied from 33.62%IACS as cast condition to 27.93%IACS for 1 pass, 24.83%IACS for 2 passes, 23.45%IACS for 3 passes. At the same time, the micro-hardness (Hv) value of Al-Ti refiner after ECAP processing has a significant increment than that of before ECAP processing.The hardness is varied from 40.1Hv as cast condition to 43.04Hv for 1 pass, 45.74Hv for 2 passes, 47.14Hv for 3 passes. The conductivity increases at first, and then becomes stable. The addition of Al-Ti system grain refiner to Al melt releases nucleant particles that promote equiaxed,which reduces columnar crystal zone,expends and refines equiaxed crystal zone of the aluminum tissues.It is concluded that the Al-Ti refiner with ECAP technique has a very useful practical application in refining industrial Al alloys.

Keywords：Al-Ti Master alloys;  ECAP;  electrical conductivity;  micro-hardness; microstructure;  refining effect