原始组织对FGH96合金热压缩变形行为和组织的影响

Effect of Original Microstructure on Thermal Compression Deformation Behavior and Microstructure of FGH96 Alloy

采用Gleeble热力模拟机分别对平均晶粒直径30μm的热等静压态、10μm的挤压态细晶和3μm的挤压态超细晶FGH96合金进行了等温压缩试验,变形温度为1000~1100℃,应变速率为0.001~0.1s-1。结果表明,在相同变形温度和应变速率下,挤压态合金的应力远小于热等静压态的,随着原始晶粒尺寸减小,FGH96合金的应力呈减小趋势,但在1100℃和0.001s-1变形时,挤压态超细晶的应力略高于挤压态细晶的;应变速率为0.001s-1时,热等静压态组织在1100℃呈现稳定流动特征,应力不随应变的增大而增大,而挤压态细晶组织在1050℃和1100℃均呈现稳态流动特征;应变速率为0.001s-1时,挤压态超细晶组织1050℃应力低于1100℃的,且晶粒组织较1100℃细小均匀,1100℃变形容易形成混晶,组织不易控制。

The isothermal compression tests of high temperature isostatic pressing(HIP)FGH96 alloy with average grain diameter of 30μm,extruded fine grained FGH96 alloy of 10μm and extruded ultrafine grained of 3μm were carried out by using Gleeble thermal simulator.The deformation temperature was 1000-1100℃.The strain rate was 0.001-0.1 s-1.The results show that the at the same deformation temperature and strain rate,the stress of extruded alloy is much smaller than that of the HIP.With the decrease of original grain size,the stress of FGH96 alloy decreases,but when it is deformed at 1100℃and0.001 s-1,the stress of extruded ultrafine grained alloy is slightly higher than that of extruded fine grained alloy.When the strain rate is 0.001 s-1,the HIP microstructure exhibits steady flow at 1100℃,and the stress does not increase with the increase of strain,while the extruded fine grain microstructure shows steady flow at 1050℃and 1100℃.When the strain rate is 0.001 s-1,the stress at 1050℃is lower than that at 1100℃,and the grain microstructure is smaller and more uniform than that at 1100℃,when the deformation temperature is 1100℃,it is easy to form mixed crystals,and the microstructure is difficult to control.