论文部分内容阅读
研究了纯铝在 3种 (A、B和C)不同等径角挤工艺中的显微组织演化。结果表明 :纯铝经过等径角挤压变形后 ,其显微组织特征与加工路线有很大的关系。提出了立方元素扭转模型 ,分析了 3种不同加工路线的剪切面和剪切方向 ,较好地解释了采用 3种不同路线挤压后材料显微组织的演化规律。在路线C(各道次挤压间试样旋转 180°)中 ,每次挤压样品总是在相同的剪切面上发生剪切 ,每相邻道次之间的剪切方向相反 ,前一次变形产生的剪切应变被随后紧接着的下一次挤压所抵消 ,这导致了多余的剪切应变 ;在路线A(各道次挤压间试样不旋转 )中 ,有两个相交成 6 0°的剪切面 ,剪切交替地在两个剪切面上进行 ;在路线B(各道次挤压间试样旋转 90°)中 ,存在 4个不同的剪切面和剪切方向 ,挤压交替地在 4个剪切面上进行 ,X ,Y和Z平面上的晶粒都发生了剪切 ,这有利于等轴晶结构的形成
The microstructure evolution of pure aluminum in three different (A, B and C) isobaric squeeze processes was studied. The results show that the microstructure characteristics of the pure aluminum after being processed by ECAP have a great relationship with the processing route. The cubic element torsional model was proposed and the shear plane and shear direction of the three different processing routes were analyzed. The evolution of the microstructure of the material after extrusion by three different routes was well explained. In Route C (180 ° rotation of the sample at each pass), each squeeze sample will always shear on the same shear plane with the shear direction reversed between each adjacent pass. The front The shear strain resulting from one deformation is offset by the subsequent subsequent extrusion, which leads to an excess of shear strain; in Route A (each sample does not rotate during extrusion), two intersect 6 0 ° shear plane, the shear alternately in the two shear planes; in the line B (each extrusion sample 90 ° rotation), there are four different shear planes and shear Direction, squeeze alternately on the four shear planes, X, Y and Z plane of the crystal are sheared, which is conducive to the formation of equiaxed crystal structure