A Ni-based superalloy, Inconel 625, is widely used for aerospace, petrochemical and marine applications due to its excellent corrosion and elevated temperature mechanical properties. In this study, efforts were made to identify optimum deposition parameters to produce directionally solidified Inconel 625 components using wire arc additive manufacturing (WAAM). Components were deposited by short-circuiting and short-circuiting with pulse mode of droplet transfers using a commercial cold metal transfer gas metal arc welding (CMT-GMAW) power source. For a given arc energy, metal droplet transfer behaviour was studied using a high-speed camera. Microstructural analysis and corrosion resistance of Inconel 625 samples produced by WAAM and samples made by conventional casting process were compared by advanced characterisation methods. Inconel 625 samples produced using a combination of short-circuiting with pulsing free flight transfers showed improved mechanical properties than as-cast samples and samples made only by short-circuiting transfer due to the formation of directionally solidified coarse-grained columnar microstructure. Moreover, corrosion resistance of WAAM samples was found to better than that of as-cast samples. Based on the results, an optimised current-voltage waveform and droplet transfer modes were identified to produce defect-free Inconel 625 deposits with desired microstructure, and mechanical and corrosion-resistance properties.

镍基超合金Inconel 625由于其出色的耐腐蚀性能和高温机械性能而被广泛用于航空航天，石油化工和船舶应用。在这项研究中，我们努力确定最佳沉积参数，以使用电弧增材制造（WAAM）生产定向凝固的Inconel 625组件。使用商用冷金属转移气体金属电弧焊（CMT-GMAW）电源，通过液滴转移的脉冲模式进行短路和短路来沉积组件。对于给定的电弧能量，使用高速相机研究了金属滴的传输行为。通过先进的表征方法，比较了WAAM生产的Inconel 625样品和常规铸造工艺生产的样品的显微组织和耐腐蚀性。通过结合短路和脉冲自由飞行转移生产的Inconel 625样品，与铸态样品和仅通过短路转移制备的样品相比，由于形成了定向凝固的粗晶粒圆柱状微结构，因此机械性能有所改善。此外，发现WAAM样品的耐腐蚀性优于铸态样品。根据结果​​，确定了优化的电流-电压波形和液滴转移模式，以生产出具有所需微结构，机械性能和耐腐蚀性能的无缺陷Inconel 625沉积物。