[en] A composite coating, containing 1.35 wt.%RE, 5.46 wt.%W, 3.82 wt.%B, 15 wt.%SiC and Ni was electrodeposited on the matrix by use of appropriate bath composition and process parameters. The addition of RE(CeO₂) enhanced the hardness and wear resistance of the coating remarkably. The hardness and wear resistance of the coating increase with a rise in heat treatment temperature, and the hardness reaches the optimum value at 400 deg. C, while the coating has the best wear resistance at 500 deg. C. The wearing tests show that the wear resistance of the coating is four to five times as high as that of hard chromium, and the corrosion tests indicate that the corrosion resistance of the coating is superior to that of 1Cr18Ni9Ti stainless steel in various corrosive media, except for nitric acid. X-ray diffraction shows that the 1.35 wt.%RE-5.46 wt.%W-3.82 wt.%B-15 wt.%SiC-Ni as-deposited composite coating is mainly amorphous, except a few Ni, W, CeO₂, B and SiC phases

[en] Copper powder is prepared by electrolysis, and additives Sodium dodecyl benzene sulfonate (SDBS) and polyvinyl pyrrolidone (PVP) are added to the electrolyte. Through the synergy effect of the two additives, the shielding effect between metal atoms is enhanced, and as a consequence the microscopic morphology is changed and it the powder performance is improved. Scanning electron microscopy (SEM), x-ray diffraction (XRD) and Electrochemical Impedance Spectroscopy (EIS) are used to characterize the copper powder. The results show that when the content of SDBS and PVP is 5 g l⁻¹ and 1.5g l⁻¹ respectively, the new type of thin and long dendrite copper powder can be obtained by electrolysis. (paper)

[en] A silver-coated copper powder with an added transition Sn layer is obtained by electroless plating, and the prepared composite powder is heat-treated under a protective atmosphere to form a transition layer by diffusion between metal atoms for improved powder properties. The effect of the transition layer on the morphology, adhesion and oxidation resistance of the copper-coated copper powder is studied. The results show that the Cu/Sn/Ag composite powder exhibits excellent plating adhesion and oxidation resistance performance when the content of the intermediate layer is 10% of Sn. (paper)