复杂钛合金进气道热等静压近净成形技术研究

Near-Net-Shaping Hot Isostatic Pressing of Complicated Titanium Alloy Air Inlet

关键词:  冲压发动机  进气道  钛合金  薄壁结构  成形技术  力学性能  热等静压

Key words:  Ramjet engine  Air inlet  Titanium alloy  Thin-walled structures  Forming techniques  Mechanical performance  Hot isostatic pressing

摘要:

冲压发动机进气道是一种复杂异形薄壁钛合金构件，成形难度非常大。以TA15钛合金粉末为原材料，利用热等静压近净成形技术在国内首次研制成功进气道，实现了整体结构的一次成形，并成功通过飞行考核。从进气道本体取样，测试了不同位置的组织。结果表明：热等静压TA15钛合金不同位置组织均匀性好，主要以板条状或片层状α相为主。在粉末颗粒边界大应变带周围分布着等轴α相，相间分布少量的细小β相。测试了材料各项性能，其平均室温抗拉强度、屈服强度、伸长率、断面收缩率、500℃抗拉强度、断裂韧性和冲击韧性分别为995MPa，924MPa，18.2%，43%，673MPa，90.6MPa·m^1/2和51.4J/cm²，各项性能数据均达到了GJB2744A-2007中规定的TA15钛合金锻件的水平，综合性能良好。

Abstract:

The air inlet of the ramjet is a complex shaped thin-walled titanium alloy component， which is very difficult to form. Using TA15 titanium alloy powder as the raw material， the air inlet was successfully developed for the first time in China by using near-net-shaping hot isostatic pressing technology. The overall structure was formed once， and the flight test was successfully passed. Samples were taken from the inlet body and microstructure at different locations were observed. The results show that the microstructure of TA15 titanium alloy is uniform at different positions， mainly lath-like or lamellar α-phase. Equivalent α-phase is distributed around the large strain zone of powder grain boundary， and a small amount of β is distributed between phases. The various properties of the material were tested. The average room temperature tensile strength， yield strength， elongation， reduction of area， 500℃ tensile strength， fracture toughness and impact toughness were 995MPa， 924MPa， 18.2%， 43%， 673MPa， 90.6MPa·m^1/2 and 51.4J/cm². All performance data have reached the level of the TA15 titanium alloy forgings standard， which show excellent comprehensive performance.