为了开发其下一代太空勘探工具，美国宇航局已大大加大了将3D打印纳入组件设计的努力。
In July, the administration’s engineers performed 30 firing tests of a bi-metallic 3D printed rocket igniter at the Marshall Space Flight Center in Huntsville, Alabama. After analysis at the University of Alabama, researchers found that the two alloys, based in copper and Inconel, fused to form a strong bond.
The demonstration has provided NASA with a promising alternative to conventional manufacturing methods, key to the momentum of its future space craft.
Bi-metallic and hybrid machined
The igniter, a part used to initiate the start sequence of a rocket engine, was hybrid machined on aDMG MORI的金属3D打印/CNC铣削系统。然而，在3D打印机的构建室内梳理两种金属确实对团队构成了重大挑战，因为它需要管理铜和inconel独有的不同属性和熔点。普雷斯顿·琼斯（Preston Jones），马歇尔太空飞行中心工程局负责人commented“这是用两种不同合金制成的3D印刷和测试火箭组件的技术成就。”
Given adequate development, Jones adds that, “This process could reduce future rocket engine costs by up to a third and manufacturing time by 50 percent.”
超强的纽带
仅10英寸高，宽7英寸，原型点火器在低压热火条件下进行了测试。之后，阿拉巴马大学的研究人员将零件切成两半，以研究显微镜下金属的内部特性。正如希望的那样，合金相互浸泡，建立了与同类点火器相媲美的牢固纽带。
Majid Babai、先进制造和铅for the project in Marshall’s Materials and Processes Laboratory, explained, “By diffusing the two materials together through this process, a bond is generated internally with the two materials and any hard transition is eliminated that could cause the component to crack under the enormous forces and temperature gradient of space travel.”
Conventionally, the part would have been produced through the brazing technique which melts a metal filler into an host joint.
Babai补充说：“消除了悬挂的过程，并在一台机器中建造双金属零件不仅会降低成本和制造时间，而且还通过提高可靠性来降低风险。”
The future of aerospace
考试是一种很有前途的发展未来的中华民国ket components. Steve Wofford, manager of美国宇航局即将出现的太空发射系统（SLS）液体发动机办公室评论说：“我们对这项新的高级制造技术将来可以为太空启动系统计划做什么。在下一代火箭发动机中，我们渴望通过3D打印技术创建更大，更复杂的飞行组件。”
California’s Aerojet Rocketdyne has also been working with NASA on its完全3D打印引擎and the ArianeGroup, a consortium of rocket builders owned by Airbus and Safran, is also using 3D printing in parts for itsPrometheus liquid oxygen (LOx)-methane engine.
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特色图像：2017年8月在NASA的Marshall太空飞行中心进行的热火测试中的3D印刷火箭部分。NASA/MSFC HOTO作者：David Olive
