应变分布的可控调整，提出阶梯型前角刀具挤出切削的新工艺。通过仿真与试验相结合，探究了6061铝合金在不同加工参数下的带材形貌、显微硬度与微观组织。同时开展常规前角刀具挤出切削作为对比试验。结果显示阶梯型前角刀具可实现超细晶带材的连续成形，且带材内部形成不同的应变分布，通过改变待切厚度可以调整高、低应变区占比。该工艺可为刀具设计与超细晶材料制备提供思路与方法。

The reduction of the tool rake angle in the extrusion machining process is conducive to increase the shear strain and grain refinement, but it easily leads to problems such as strip extrusion difficulties and poor surface quality. To improve the forming quality of ultrafine-grained aluminum strips and to realize the controllable strain distribution adjustment, a new process of extrusion machining with a stepped rake angle tool is proposed. By combining simulation and experiments, the strip morphology, microhardness and microstructure of 6061 aluminum alloy under different machining parameters are investigated. Extrusion machining with conventional rake angle tool is also carried out as a comparative test. The results show that the stepped rake angle tool achieves the continuous formation of ultrafine-grained strip with different strain distributions within the strip, and the ratio of high and low strain zones is adjustable by changing the thickness to be cut. This process can provide ideas and methods for tool design and ultrafine-grain material preparation.