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采用无坩埚感应熔炼超声气体雾化法制备Ti-5Al-2.5Sn ELI预合金粉末,并对预合金粉末进行表征.研究了热等静压参数对Ti-5Al-2.5Sn ELI粉末合金显微组织和力学性能的影响.结果表明,热等静压温度和压力的升高有助于提升粉末合金的致密度,当粉末合金的致密度大于99.5%时,粉末合金的力学性能可以达到锻造合金的水平.综合考虑粉末合金的致密度、显微组织和力学性能,Ti-5Al-2.5Sn ELI预合金粉末优选的热等静压工艺成型窗口为温度890~940℃,压力120 MPa以上,保温保压3 h.包套对热等静压压力有屏蔽作用,设计不当会降低粉末压坯的致密度.通过优化包套设计、热等静压参数和工艺途径可以有效抑制包套的屏蔽作用,提升粉末合金的致密度.
The Ti-5Al-2.5Sn ELI pre-alloyed powders were prepared by a non-crucible induction melting ultrasonic gas atomization method, and the pre-alloyed powders were characterized.The effects of hot isostatic pressing parameters on the microstructure of Ti-5Al-2.5Sn ELI alloy The results show that the increase of the temperature and pressure of hot isostatic pressing can promote the density of the powder alloy. When the density of the powder alloy is more than 99.5%, the mechanical properties of the powder alloy can be as high as forged alloy Level.According to the density, microstructure and mechanical properties of the powder alloy, the preferred hot isostatic pressing window of the Ti-5Al-2.5Sn ELI pre-alloyed powder is at a temperature of 890-940 ℃ and a pressure of 120 MPa, Pressure 3 h.The sheath has a shielding effect on the hot isostatic pressure, improper design will reduce the density of the powder compact.By optimizing the sheath design, hot isostatic pressing parameters and process can effectively inhibit the shielding effect of the sheath, Improve the density of the powder alloy.