Tensile properties of NAB materials after HIP.

Nickel aluminium bronze (NAB) alloys are known for their excellent strength and corrosion resistance, making them suitable for maritime and industrial applications. NAB is producible by Powder Metallurgy (PM) but typically requires high compaction pressure. The objective of this study is to investigate the manufacturing of NAB using the cold spray additive manufacturing (AM) process and to compare its properties to those produced by traditional methods such as casting and PM. Cold spray is a solid-state coating technique that accelerates powdered metal and carrier gas to supersonic speeds, enabling bonding through plastic deformation. Binary aluminium bronze (AB) and NAB alloys were produced using powders by cold spraying powders into 3D printed parts, and heat treating the resulting parts. The AB alloy contained blended 9.9% aluminium alloy (Al6061) powder and copper powder, while the NAB alloy included 11% Al6061 powder, 5.8% nickel powder, 6.8% iron powder, and copper powder. Powders were mixed under controlled conditions and deposited using a LightSPEE3D printer and compressed air. Post-deposition heat treatments, such as homogenisation, aging, and/or hot isostatic pressing (HIP), were applied to enhance material properties. The results indicate that the cold spray process, combined with appropriate heat treatments, can produce NAB alloys with desirable microstructures containing fine κ phases and mechanical properties with above 280 MPa yield strength, above 500 MPa tensile strength and 20% elongation which are comparable to those achieved by traditional cast methods which yield strength of 240 MPa, tensile strength of 580 MPa and 15% elongation, and superior to PM methods. This study demonstrates the viability of cold spray AM to enhance the production of complex high-strength alloys, offering significant advancements for maritime and industrial applications.镍铝青铜（Nickel Aluminium Bronze, NAB）合金以其优异的强度与耐蚀性能，适用于海事与工业领域。镍铝青铜可通过粉末冶金（Powder Metallurgy, PM）工艺制备，但通常需要较高的成型压力。本研究旨在探索采用冷喷涂增材制造（Cold Spray Additive Manufacturing, AM）工艺制备镍铝青铜合金的可行性，并将其性能与铸造、粉末冶金等传统工艺制备的合金进行对比。冷喷涂是一种固态涂层技术，通过将金属粉末与载气加速至超音速，借助塑性变形实现粉末间的结合。本研究通过冷喷涂工艺将粉末沉积为三维成型件并经后续热处理，制备了二元铝青铜（Binary Aluminium Bronze, AB）与镍铝青铜合金。其中二元铝青铜合金由9.9%的Al6061铝合金粉末与铜粉混合制成；镍铝青铜合金则包含11%的Al6061铝合金粉末、5.8%的镍粉、6.8%的铁粉以及铜粉。所有粉末均在受控条件下混合均匀，并通过LightSPEE3D打印机与压缩空气完成沉积。为优化材料性能，对沉积后的构件实施了均质化、时效以及/或热等静压（Hot Isostatic Pressing, HIP）等后处理工艺。研究结果表明，冷喷涂增材制造工艺配合适宜的热处理方案，可制备出含有细小κ相的优质微观组织，其力学性能表现为屈服强度超过280 MPa、抗拉强度超过500 MPa、断后伸长率达20%。该性能优于传统粉末冶金工艺制备的合金，且与传统铸造工艺（屈服强度240 MPa、抗拉强度580 MPa、断后伸长率15%）的性能水平相当。本研究证实了冷喷涂增材制造工艺可用于高效制备复杂高强度合金，为海事与工业领域的应用提供了重要的技术提升路径。