Hot corrosion is one of the crucial failure modes of Ni-based superalloy components operating at high temperatures, which inevitably affects the subsequent mechanical properties of the alloys. In this research, damaged Inconel 718 alloy components with a pre-made trapezoid groove are repaired using laser additive manufacturing technique, and the change mechanisms of the microstructure and tensile properties of the repaired Inconel 718 alloy due to the hot corrosion in the salt mixture of 87.5 wt.% Na₂SO₄ + 5 wt.% NaCl + 7.5 wt.% NaNO₃ at 650 °C for different durations are investigated. The results show that oxidation and Cr-depletion occur on the repaired components due to the hot corrosion, and the corrosion products are mainly composed of Cr₂O₃, Fe₃O₄, and Ni₃S₂. The tensile strength and elongation of the as-repaired specimens are 736.6 MPa and 12.5%, respectively. After being hot corroded for 50 h, the tensile strength increases to 1022.9 MPa and elongation decreases to 1.7%. However, after being hot corroded for 150 h, both tensile strength and elongation of the repaired specimens drop to 955.8 MPa and 1.2%, respectively. The mechanical performance alteration is highly related to thermal effects instead of the molten salt attack.

The influence of microstructures of the two TC4 substrates on the growth process and properties of micro-arc oxidation (MAO) coatings were investigated and compared. The morphologies, thickness, roughness and compositions of the coatings on forging-TC4 (F-MAO) and SLM-TC4 (S-MAO) were characterised by scanning electron microscopy, atomic force microscopy, energy-dispersive spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The SLM-TC4 exhibits needles of α′ phase, while forging-TC4 have distinct α and β phases. The results show that α′ phase of SLM-TC4 causes the discharge channels to be uniform during MAO process, making S-MAO free of cracks. The S-MAO coating has smaller pores and lower roughness, but thicker than that of F-MAO coating. S-MAO coating has better corrosion resistance and biological activity than that of F-MAO in SBF.

Porous TiO2 ceramic coatings with high contents of Si and P were fabricated on a Ti6Al4V alloy using hybrid processing of laser surface melting (LSM) and microarc oxidation (MAO). The effect of LSM pretreatment on the growth behavior and mechanical properties of the MAO coating was studied. The results showed that the MAO coating on LSM pretreatment Ti6Al4V (LSM-MAO) had quite different surface morphologies, thickness, and compositions compared to the MAO coating on as-received titanium alloy. Grain refinement and dislocation in the LSM-treated Ti6Al4V alloy provided extra energy and more numbers of discharge channels during the MAO process. LSM–MAO coating exhibited a more uniform pore distribution, relatively small pores, and larger thickness compared to the MAO coating. The LSM-MAO coating had higher hardness and better wear resistance than the MAO coating. LSM is deduced to be an appropriate and efficient pretreatment method for achieving a high-quality MAO coating on titanium alloy.

To gain sustainable development, it is a trend that manufacturing companies are change the value chain from manufacturing-centric to service-centric. Therefore, the capability of the manufacturing service is as significant as the production ability of enterprises, which reflects the supply chain management (SCM), flexible production, production efficiency, and other indicators of the enterprises. It is the first paper to discuss the sustainability of service-oriented manufacturing using bibliometric analysis. It derives a detailed review and future outlook on the development of manufacturing servitization, indicating the research directions for future development, and provides a valuable reference for researchers in related directions. The bibliometric analysis discusses countries or regions, research areas, authors, keywords, institutions, and journals based on the literature data from the Web of Science (WoS). The results show that research on manufacturing services has gradually received attention since its inception and has become popular since 2008. The papers published from 2008 to 2021 account for 77.62%. The USA is the most studied country on this topic, followed by China and the UK. The International Journal of Production Research regarding the most quantity of articles, and Beihang University is the most influential institution in this field. The largest amount of articles published in the area of “business and economics”, amounting to 1565 articles. In recent years, the main research areas included “Industry 4.0”, “cloud manufacturing (CMfg)”, “Internet of Things (IoT)”, “big data” and “services innovation”. Finally, “digital and intelligent manufacturing” and “product-service systems” are potential research directions for the future.

Stellite 6 alloy hardfacing has been popularly applied on the seat face of control valves where both wear and corrosion in various corrosive media are involved. In this research, Stellite 6 alloy hardfacing is prepared via laser cladding and the wear performance and corrosion behavior in morpholine, 3.5 wt % NaCl, and Green Death solution, of this hardfacing are investigated using a pin-on-disc tribometer and a three-electrode cell, respectively. The worn and corroded surfaces are analyzed using SEM/EDS. For comparison, cast Stellite 6 is also studied in parallel. The experimental results show that cast Stellite 6 has better wear resistance than laser clad Stellite 6 but better corrosion resistance in the corrosive media due to better retention of the oxide film on the specimen surface.