Research into Shear Deformation-added Extrusion of Metal-based Powder Using Separated Rotary Container

考虑到剪切变形的加入能促进金属粉末之间的粘附性，设计了一种分离式旋转容器，对其实现进行了实验研究。通过对粒度为20-42目的铝粉理想引入剪切变形的基础实验发现，对于一种形状的旋转容器，其筒体长度L应大于容器腔体六角形截面的最短对角线距离D，并且容器的转速应根据作用于剪切部位的压力设置如下：压力为98MPa和147MPa时，闸板每转一圈应大于5mm， 1.5mm。在此基础上，采用所设计的挤压方法分步操作，对铝粉进行了连续固结试验。实验采用截面积减少11.5%的挤压模，在147MPa压力下形成预压紧的粉坯进行喂料。与预期相反，所有的试验都以失败告终。失效的原因是挤压力急剧增大，使铝粉侵入容器与冲床之间的空隙，阻碍了物料的连续进料。实验的失败使研究加工条件对产品性能的影响受阻。然而，实验表明，由于剪切变形的引入，坯料之间产生的边界完全可以消除。本研究前一部分的研究结果已经发表，后一部分的研究结果还没有发表。

Shear deformation-added extrusion of metal-based powder using a separated rotary container devised taking note of the promotion of adhesion between metal powders by shear deformation addition was experimentally studied for its realization. From fundamental experiments on ideal introduction of the shear deformation with aluminum powder whose size is 20-42 in mesh, it was found that concerning a shape of the rotary container its barrel length L should be more than the shortest diagonal distance D of the hexagonal cross-section of the container cavity and that the rotating rate of the container should be set as follows, depending on the pressure acting on the shearing site. Ram travel a revolution of the container should be more than 5mm and 1.5mm when the pressure is 98MPa and 147MPa, respectively. Based on the findings above, continuous consolidation of the aluminum powder by means of step-by-step operation of the devised extrusion method was experimented. In the experiment, an extrusion die with a cross-sectional reduction of 11.5% was used and material feeding was done with pre-compacted powder billets formed by the pressure 147MPa. Contrary to expectation, all the experiments tried ended in failure. The cause of the failure is a sharp increase of extruding force, which made an intrusion of the aluminum powder into the gap between the container and punch and prevented the successive feeding of the material. The failure of the experiment prevented the influence of processing conditions on product's property from being investigated. However, the experiments showed that the boundary produced between the billets fed is completely removable by the introduction of the shear deformation. The findings in the former part of this study have been published, but those in the latter have not yet.