直接热等静压粉末Udimet 720合金的组织与性能

铸锻U720合金已被广泛用作发动机涡轮盘材料.最近研究发现挤压加等温锻的粉末冶金U720也有很好的性能.本文研究了热等静压加热处理(即直接热等静压状态)粉末U720合金的拉伸、持久及低周疲劳性能.研究表明,直接热等静压粉末U720合金的性能与变形(挤压加锻造)合金的相当,可用于发动机涡轮盘.这种不需要挤压和锻造的近净尺寸成型工艺正适应了目前不断降低成本的要求.

MICROSTRUCTURE AND PROPERTIES OF AS-HIPED P/M UDI MET 720

UDIMET alloy 720 has conventionally being used as cast or wrought material for turbine disks.Recent studies have identified that the combination of extrusion and isothermal forging (E+I) for P/M material can also result in excellent properties for P/M UDIMET alloy 720.In this present work,P/M UDIMET 720 was prepared by hot isostatic pressing,and heat treating(i.e.,as HIPed).This type of processing can produce near net shapes without extrusion and forging steps,thus reduced the cost.Tensile properties,creep rupture strength and LCF properties of the as HIPed material were evaluated.Results shown that as HIPed P/M UDIMET alloy 720 has equivalent properties to the E+I P/M material,so it may be suitable for engine applications.