With the development of the aerospace and automotive industries, high heat exchange efficiency is a challenge facing the development of various industries. Pure copper has excellent mechanical and physical properties, especially high thermal conductivity and electrical conductivity. These excellent properties make pure copper the material of choice for the manufacture of heat exchangers and other electrical components. However, the traditional processing method is difficult to achieve the production of pure copper complex parts, so the production of pure copper parts through additive manufacturing has become a problem that must be overcome in industrial development. In this article, we not only reviewed the current status of research on the structural design and preparation of complex pure copper parts by researchers using selective laser melting (SLM), selective electron beam melting (SEBM) and binder jetting (BJ) in recent years, but also reviewed the forming, physical properties and mechanical aspects of pure copper parts prepared by different additive manufacturing methods. Finally, the development trend of additive manufacturing of pure copper parts is also prospected.

Bulk metallic glasses (BMGs) are a subject of interest due to their superior specific properties such as low coefficient of friction, high strength, large ductility in bending, high elastic modulus, high microhardness, and high resistance to corrosion, oxidation, wear, and so on. However, BMGs are difficult to apply in industry due to their difficulty in manufacturing and secondary operation. In the past few decades, many efforts have been carried out to overcome the defects in the manufacturing of BMGs. It is difficult to fabricate complex structures with the whole amorphous alloy owing to the limit of crystallization and critical cooling rate. Additive manufacturing (AM), such as selective laser melting (SLM), can obtain relatively high cooling rates during the “layer-by-layer” process, which makes it possible to surpass the dimensional limitation of metallic glass. In the SLM process, the high-speed cooling of molten pool and the avoidance of secondary processing are very beneficial to the production and application of amorphous alloys. In this paper, based on the research of SLM additive manufacturing BMGs in recent years, the factors affecting crystallization and forming ability are discussed from many aspects according to different material systems. The status and challenges of SLM manufacturing BMGs including Fe-based, Zr-based, Al-based, and some composite-based BMGs will be presented. Mechanical properties and physicochemical properties were introduced. This review aims to introduce the latest developments in SLM additive manufacturing BMGs, especially on the development of process parameters, structure formation, simulation calculation, fracture mechanism, and crystallization behavior. With the traditional fabricating methods, BMGs were mainly used as a structure material. It will provide another alternative to use BMGs as a functional material by introducing SLM technology in amorphous preparation with complex geometry. This review summarizes the technical difficulty and application prospects of BMGs preparation by SLM and discusses the challenges and unresolved problems. This review identifies key issues that need to be addressed in this important field in the future. These problems are related to the application of BMGs as high-strength structural materials and new functional materials in the future.

In this study, a combination of Al–12Si and Al–20Si (Al–(12-20)Si) alloys was fabricated by selective laser melting (SLM) as a result of increased component requirements such as geometrical complexity and high dimensional accuracy. The microstructure and mechanical properties of the SLM Al–(12-20)Si in as-produced as well as in heat-treated conditions were investigated. The Al–(12-20)Si interface was in the as-built condition and it gradually became blurry until it disappeared after heat treatment at 673 K for 6 h. This Al–(12-20)Si bi-material displayed excellent mechanical properties. The hardness of the Al–20Si alloy side was significantly higher than that of the Al–12Si alloy side and the disparity between both sides gradually decreased and tended to be consistent after heat treatment at 673 K for 6 h. The tensile strength and elongation of the Al–(12-20Si) bi-material lies in between the Al–12Si and Al–20Si alloys and fracture occurs in the Al–20Si side. The present results provide new insights into the fabrication of bi-materials using SLM.

TiN and WS₂ + hBN reinforced Ni-based alloy self-lubricating composite coatings were fabricated on TC4 alloy by laser cladding using TiN, NiCrBSi, WS₂, and hBN powder mixtures. Energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffractometry (XRD), and optical microscopy (OM) were adopted to investigate the microstructure. The wear behaviors of the self-lubricating composite coatings were evaluated under large contact load in room temperature, dry-sliding wear-test conditions. Results indicated that the phases of the coatings mainly include γ-Ni, TiN, TiNi, TiW, WS₂, and TiS mixtures. The average microhardness of the composite coating is 2.3–2.7 times that of the TC4 matrix. Laser cladding TiN/WS₂ + hBN/NiCrBSi self-lubricating composite coatings revealed a higher wear resistance and lower friction coefficient than those of the TC4 alloy substrate. The friction coefficient (COF) of the coatings was oscillating around approximately 0.3458 due to the addition of self-lubricant WS₂ + hBN and hard reinforcement TiN. The wear behaviors testing showed that the wear resistance of the as-received TC4 was significantly improved by a laser cladding TiN/WS₂ + hBN/NiCrBSi self-lubricating composite coating.