半固态AZ91D镁合金的压缩变形和显微组织

利用平行板触变压缩仪研究了电磁搅拌的半固态AZ91D合金试样的压缩变形和组织.结果表明:随着半固态压缩变形温度的升高,AZ91D镁合金试样变形的速度加快,即变形应变速度增大,但压缩应力不断下降;在某一载荷下,AZ91D镁合金试样压缩变形应力和应变呈明显的线性关系,与压缩温度的高低无关.随着半固态压缩载荷的提高,AZ91D镁合金试样变形的速度增加,应变速度增大,应力下降速度加快;在不同的压缩载荷下,AZ91D镁合金试样的压缩变形应力和应变都呈明显的线性关系.在实验中的各种半固态压缩变形条件下,初生α-Mg在压缩后AZ91D镁合金试样组织中的分布很均匀,几乎不存在组织偏析.当初生固相的形态呈球状结构,在相同的变形条件下,不同种类合金的半固态压缩变形规律非常相似.

Compressing deformation and microstructure of semi-solid AZ91D magnesium alloy

The compression tests and microstructures of semi-solid AZ91D magnesium alloy have been conducted on a parallel-plate viscometer. The results show that with the compression temperature increasing the deformation rate or the strain rate of the AZ91D magnesium alloy samples rises, but the compressing stress continuously decreases. The deformation strain is obviously linear with the compressing stress and independent from the compression temperatures under a given compression load. In the wake of the compression load being added, the deformation rate or the strain of the AZ91D magnesium alloy samples increases and the compressing stress decreases clearly. The deformation strain is obviously linear with the compressing stress of the corresponding sample under different compression loads. The primary a-Mg grains are evenly stretched in the microstructure of the compressed AZ91D magnesium alloy samples and there is not almost microstructural segregation whenever the compression condition varies. The results also show that the compression regularities of different alloys are very similar if the primary crystals are spherical and the samples are deformed under the same semi-solid condition.