Abstract

An innovative manufacturing method to fabricate tubular parts made of tungsten heavy alloy (THA) by diffusion bonding of sintered semicircular tubes is proposed and characterized in this study. THAs are produced by blending tungsten grains with a lower-melting-point Ni-Fe binder metal. During the liquid phase sintering (LPS) process of THA, the Ni-Fe liquid wets the tungsten and provides a soluble diffusion network for rapid sintering. Multi-phase THAs are usually very difficult to produce as a tubular piece. During the LPS of the powder compact, a gravity-induced slumping leads to some distortion in the bottom of the tubular parts. One possible alternative to handle this problem is to combine the segmented THA pieces by solid-state diffusion bonding to build up tubular piece. Thus, this study proposes combining the semicircular THA tubes using the diffusion bonding technique to manufacture the tubular THA parts. To provide uniform contact pressures along the joining surfaces, horizontal diffusion bonding is performed using a specially constructed supporting apparatus to reduce the gravity effect. An industry-applicable tube manufacturing process has been well characterized, and its feasibility has been demonstrated by bond quality that was assessed by optical metallography and mechanical testing.

中文翻译：

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半圆管的扩散结合制造钨合金管

摘要

提出了一种创新的制造方法，该方法通过烧结半圆管的扩散结合来制造钨重合金（THA）制成的管状零件。THA是通过将钨晶粒与较低熔点的Ni-Fe粘结剂金属混合而制成的。在THA的液相烧结（LPS）过程中，Ni-Fe液体润湿了钨，并提供了可溶的扩散网络以进行快速烧结。多相THA通常很难制成管状件。在粉末压块的LPS期间，重力引起的塌落会导致管状零件底部出现一些变形。处理该问题的一种可能的替代方法是通过固态扩散结合将分段的THA件组合起来，以形成管状件。从而，本研究建议使用扩散结合技术将半圆形THA管组合在一起，以制造管状THA零件。为了沿接合表面提供均匀的接触压力，使用特殊构造的支撑设备执行水平扩散接合以减小重力作用。一个行业适用的管材制造工艺已得到充分表征，其可行性已通过光学金相和机械测试评估的结合质量得到证明。