| 1. | Secondly , the effect of transverse deforming on the property of the wedge pressing was studied . the results showed that : the wedge pressing stock with the transverse deforming amount of 10 % acquired the best performance . the highest density got the biggest rate of slope while with the amount of 30 % the curve was more some special structure and performance as following : the large porosities was crushed into small or linear ones with the high - direction deformation amount of 20 % ; as the increasing of the high - direction deforming , the particles got a further deforming , the porosities got a further crushing , the small porosities were mergered by the large ones and the former then disappeared ; when the amound reached 60 % , the quantity of the porosities would obviously decrease which made the materials compact , the microstructure more uniform and the density and hardness curves more horizontal , the relative desity could reach 99 . 7 % , the tensile strength b of the as - compacted samples reached 408mpa with the yield strength s teached 289mpa and the elongation percentage reached 13 . 6 % . in addition , the microstructure of the wedge pressing stock under the pressing temperectureof 450 was uniform , the porosities and the boundries of the grains basically disappeared and the conjunction between particles was great
采用双向楔形压制,大尺寸喷射沉积5a06铝合金楔压坯的组织和性能变化具有如下特点:当高向变形量为20 %时,大的孔洞变形破碎为小的孔洞,或呈线状孔;随着高向变形量的增加,颗粒进一步变形,孔洞进一步破碎,大孔“吞并”小孔,小孔塌陷并逐步消失;当高向变形量达到60 %时,孔洞量大为减少,材料基本致密,组织趋于均匀,楔压坯料的密度、硬度变化曲线接近水平线,坯料的相对密度达99 . 7 % ,抗拉强度_ b = 408mpa ,屈服强度_ ( 0 . 2 ) = 289mpa ,延伸率= 13 . 6 % ;对比其它的压制温度,在450楔形压制的坯料组织均匀,孔洞及颗粒边界基本消失,颗粒之间冶金结合良好。 |
