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.

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Hydrogenated nitrile rubber (HNBR)/silica nanocomposites were prepared by in-situ modification dispersion technology, and the silane coupling agent c-methacryloxypropyl trimethoxy silane (KH570) was chosen to promote the interfacial strength between silica particles and HNBR matrix and further improve the dispersion of silica particles. Rubber Process Analyzer (RPA2000) was used to test the Payne effect of HNBR/silica compounds, from which some interesting phenomena were found: the Payne effect became stronger after KH570 was added to HNBR/ silica compound at room temperature, which was a contrary result compared to SBR/silica system. However, after stored for a month at room temperature, the Payne effect weakened, which was contrary to the traditional phenomenon of storage hardening of filled rubber. All these results are related to filler-filler interaction and filler-rubber interaction. The modulus at small strain amplitude of HNBR/ silica compound with KH570 gradually decreased with the increase of times of circulatory strain sweep but that of compound without KH570 had almost no change, which was explained by Fourier Transform Infrared (FTIR) results that the reaction between silica and KH570 almost completed at the test condition: 80 C and about 1 h. The effects of silane amount, heat-treated temperature and time on the Payne effect of compounds and the mechanical properties of vulcanizates were also investigated. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124: [927][928][929][930][931][932][933][934] 2012

A fully continuous-flow diazotization−hydrolysis protocol has been developed for the preparation of p-cresol. This process started from the diazotization of p-toluidine to form diazonium intermediate. The reaction was then quenched by urea and subsequently followed by a hydrolysis to give the final product p-cresol. Three types of byproducts were initially found in this reaction sequence. After an optimization of reaction conditions (based on impurity analysis), side reactions were eminently inhibited, and a total yield up to 91% were ultimately obtained with a productivity of 388 g/h. The continuous-flow methodology was used to avoid accumulation of the highly energetic and potentially explosive diazonium salt to realize the safe preparation for p-cresol.

Wire arc additive manufacture (WAAM) technology has attracted more and more attention. WAAM technology provides a way to manufacture a large‐scale part at a low cost and with less material loss. Inconel 625 alloys are widely used for their excellent mechanical properties and corrosion resistance. Therefore, it is important to investigate the performance of Inconel 625 alloy in WAAM. Herein, cold metal transfer (CMT) arc is used as the heat source to fabricate thick‐walled parts of Inconel 625 alloy by WAAM, and study the difference between microstructure and mechanical properties under the different torch trajectories. The result shows that the grains inside the parts are all thick dendrites and show the trend of epitaxial growth. The thermal input of the oscillation additive is higher than the two‐pass multilayer additives, and the Laves phase also precipitated more. The maximum tensile strength occurs in parallel sampling close to the substrate, which is 693.5 ± 12.6 and 751.2 ± 17.6 MPa in oscillation and two‐pass multilayer modes, respectively. The maximum elongation is obtained in the vertical direction is 60 ± 1.0% and 60 ± 1.1%. The anisotropies are 4% and 4.5%, respectively. The maximum hardness value under the two torch trajectories also appears close to the substrate.

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