Yingna WU
,
Gang ZHANG
,
Bingchun ZHANG
,
Zhongchao FENG
,
Yong LIANG
,
Fangjun LIU
材料科学技术（英）
Two types of plasma sprayed coatings (NiCrAlY and NiCrAlY-Al2O3) were remelted by a 5 kW cw CO2 laser. With increasing laser power and decreasing traverse speed in the ranges of 200 similar to 700 W and 5 similar to 30 mm/s respectively, the melted track grew in width and depth. In the optimum range of laser parameters, a homogeneous remelted layer without voids, cavities, unmelted particles and microcracks was formed. On the surface of remelted layers, Al2O3 and YAlO3 were detected. As a result of isothermal oxidation tests, weight gains of laser remelted coatings were obviously lower than that only plasma sprayed, especially laser remelted NiCrAlY-Al2O3 coatings. The effects of laser remelting and incorporation of Al2O3 second phase in NiCrAlY matrix on high temperature oxidation resistance were discussed.
关键词:
Yibin REN
,
Ke YANG
,
Bingchun ZHANG
,
Yaqing WANG
,
Yong LIANG
材料科学技术（英）
BIOSS4 steel is essentially a nickel-free austenitic stainless steel developed by the Institute of Metal Research, Chinese Academy of Sciences, in response to nickel allergy problems associated with nickel-containing stainless steels that are widely used in medical applications. The high nitrogen content of this steel effectively maintains the austenitic stability and also contributes to the high levels of corrosion resistance and strength. BIOSS4 steel possesses a good combination of high strength and toughness, better corrosion resistance, and better blood compatibility, in comparison with the medical 316L stainless steel. Potential applications of BIOSS4 steel can include medical implantation material and orthodontic or orthopedic devices, as well as jewelries and other decorations.
关键词:
Medical stainless steel
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Yanjin LU
,
Lili TAN
,
Hongliang XIANG
,
Bingchun ZHANG
,
Ke YANG
金属学报(英文版)
A composite coating was fabricated on pure magnesium by hydrothermal treatment in order to reduce its degradation in body environment. The coating was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD pattern showed that the main composition of the coating was a mixture of CaSiO3, MgSiO3 and Mg(OH)2. Electrochemical test showed that the corrosion current density (emcorr) of the coated magnesium was decreased by about two orders of magnitude compared with that of the bare magnesium, and the EIS measurement also showed that the corrosion resistant performance of the coated magnesium was significantly enhanced. Meanwhile, weight loss test showed that the weight loss of the coated magnesium was lower than that of the bare magnesium. Hence, the present study indicated that the composite coating could greatly slow down the degradation of pure magnesium.
关键词:
Magnesium
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