成形工艺对快速凝固Al-Cu-Mg合金组织和性能的影响
INFLUENCE OF FORMING PROCESS ON MICROSTRUCTURE AND PROPERTIES OF RAPIDLY SOLIDIFIED Al-Cu-Mg ALLOY
-
摘要: 采用自制离心雾化装置制取了快速凝固LY12硬铝合金粉末,研究了以该粉末制成的真空热压件和挤压丝材的组织和性能。结果表明,所得粉末为泪滴状,其显微组织为树枝状晶和胞状晶。真空热压件密度高时所对应的强度高。450℃、10min、150MPa为较合理的工艺,此时粉末颗粒间结合密实,晶粒尺寸没有明显改变。在500℃热挤压时,挤压丝的组织已发生了再结晶,晶粒尺寸仍较细小。挤压丝材的抗拉强度达460MPa,其断口为韧窝状,韧窝尺寸小于3μm,且分布均匀。Abstract: LY12 rapidly solidified hard aluminium powder has been obtained by using self-made centrifugal atomizing apparatus and the structures and properties of the vacuum hot-pressed compacts and extruded wires made by such powder have been studied. The results have shown that the powder obtained is of tear-shape and its microstructures are of dendrite and cellular grains. The vacuum hot-pressed compacts with high density have highest strength. More reasonable technological parameters are 450℃, 10min and 460MPa, with which powders were densely consolidated and no obvious grain size change. Recrystallization was aroused in the structure of extruded wires with still finer grains. The tensile strength of extruded wire materials amounts to 460MPa with dimpled fracture surface. The size of dimples is below 3μm and why homogenious.