Fabrication of High Pressure Rocket Combustor by Powder Metallurgy

研究了采用烧结外壳制造高压长寿命火箭推力室的工艺条件。由于粉末冶金工艺在性能控制和成形方面的可行性，因此有选择地采用粉末冶金工艺。研究了Al-Cu系和CuAg系合金在推力室壳体上的组织控制和力学性能测试。建立了模拟实际火箭推力室的喉部模型，计算了壳体与铜质内壳的结合强度。尤其是对烧结壳体气孔率的控制，有效地降低了烧结体的硬度，保证了火箭发动机的长寿命使用。镀锡或镀银能有效地改善烧结壳体与铜内喉道之间的结合。通过控制烧结过程中的液相形成和加压，实现了足够的结合强度和无缺陷的结合界面。采用更为真实的喉道模型，对壳体与壳体之间的粘结行为进行了较为深入的研究。在喉咙处经常可以观察到粘合不足。通过适当的加压和液相形成条件，消除了模型直线段的肩部和边缘。

The processing conditions for the fabrication of high pressure and long life rocket thrust chamber with sintered outer shell were investigated. Powder metallurgical route was selectively employed because of its viability of property control and shape forming. The microstructural control and mechanical property measurements were studied on the alloy systems of of Al-Cu and Cu-Ag for the application to the outer shell of the thrust chamber. The bonding strength of the sintered interface between the outer shell and copper inner shell, as well as net shaping of throat model which simulates the actual rocket thrust chamber. Perticular attention was paid on the control of the porosity of sintered outer shell, which is effective for the lower stiffness of the sintered shell and thus ensures long life use of the rocket engine.The plating of tin or siler was found to be effective for an improved bonding between sintered outer shell and the copper inner throat. A sufficient bonding strength, as well as deffect-free bonding interface, was realized by the control of liquid phase formation and pressurizing during sinter-bonding. The bonding behavior between the outer and inner shell was studied more in datail using a more realistic throat model. Insufficient bonding was often observed at the throat. the shoulder and the edge of the straight part of the model ; which were eliminated by proper conditions of the pressurizing and liquid phase formation.