The table of L9 (34) of orthogonal design was adopted in the experiment. The optimal formulation and process conditions of electroless nickel plating on high strength aluminum alloy were determined. The influences of bath composition and operating conditions on the hardness and deposition rate were analyzed and discussed. The experimental results show that the optimal plating formulation were obtained, which were consisted of nickel sulfate hexahydrate(25g/L), sodium hypophosphite(20g/L) and sodium acetate(15g/L). The operating conditions are as follows: 80~85°C, pH value 5.0. The coating structure is more homogenous and compact, and the coating has good brightness. Meanwhile, the hardness is up to 376.8HV, and the deposition rate is 17.2μm/h. The order of effects on hardness is pH value, sodium acetate, sodium hypophosphite and nickel sulfate concentration in turn. The hardness of coating decreased after heat treatment on low temperature. When the temperature exceed 200°C, the hardness increased with temperature rising and reached the peak value at 400°C(565.3HV).

Laser surface cladding is a material processing technique to overlay the precursor material with the substrate to form a sound chemical and metallurgical bonding. Recently, laser cladding technique has been introduced in the bioceramic coating field. This paper presents a new technology to obtain bioceramic composite coating on Ti6Al4V substrate by Nd-YAG laser cladding. The microstructures of the mixed powders and cladding layer were investigated by scanning electron microscopy, and the compositions were analyzed by electron diffraction spectroscopy. The phases of the mixed powders and cladding layer were clarified by X-ray diffraction technology. Composite coating including HAP,Ca2P2O7,Ca3(PO4)2 and calcium titanates was successfully obtained by Nd-YAG laser cladding with pre-depositing mixed powders of CaHPO4·2H2O and CaCO3 directly on Ti6Al4V substrate. The average grain size of the mixed powders is 3μm from the image analyse software. The most important parameter that affected the completion of laser cladding was the scanning speed.

Process of solution treatment of 6061 aluminum alloy was done by hardness test and microanalysis in this paper. The effects of different solution treatment temperature on the microstructure and mechanical properties of 6061 aluminum alloy were studied and the influence of overburning on the microstructure and mechanical properties of 6061 aluminum alloy were also analyzed. The experimental results show that overburning occurring while 6061 aluminum alloy is heated above 580°C . The hardness measurements and microstructure analysis results show that the hardness decreased, grain boundary becomes trigemanal and compounded –melting structure (burnt structure) appeared when overburning occuring for this alloy .

Vinyl-endblocked polyurethanes were prepared from polyether diols(N210), isophorone diisocyanate (IPDI), dimethylol propionic acid (DMPA) and 2-hydroxyethyl acrylate (HEA). The core-shell structure acrylic-polyurethane composite emulsion was prepared by seeded emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA) using the polyurethanes emulsions as seeded emulsions. The core and shell regions were occupied by acrylic polymer and polyurethane, respectively. Because polyurethanes were vinyl-endblocked, acrylic monomers could graft partially to them. The formation of core-shell structure was observed by transmission electron microscopy (TEM). The structure and properties of dried film were studied by Fourier-transform infrared spectroscopy (FT-IR) and TGA.

With isophorone diisocyanate (IPDI) and polyether diols (N210) as raw, the water-borne polyurethane was synthesized. The end groups of the water-borne polyurethane were blocked with 2-hydroxyethyl acrylate (HEA). The chemical structures were characterized from Fourier Transform infrared spectroscopy (FTIR). The viscosity of the emulsion was investigated from rotary viscometer. The kinetics of reaction of NCO blocked with HEA was investigated, the results show that the reaction fits to a second-order reaction characteristic and the reaction rate is irrelevant with HEA.