Yali LI
,
Yong LIANG
,
Kesheng XIAO
,
Fen ZHENG and Zhuangqi HU(State Key Laboratory of Rapidly Solidified Nonequlibrium Alloys
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
110015
,
China)
材料科学技术（英）
High quality ultrafine Si powders have been synthesized from SiH4 by laser induced gas phase reaction. The powders prduced under different synthesis conditions have mean particle size of 10-120nm in diam. with narrow particle size distribution, and free of hard agglomerates.The powders are polycrystalline with the ratio of mean grain to particle diameter being between 0.3-0.7. The size of the powder increases with increasing laser power and reaction pressure,but decreases with increasing silane gas flow rate and the addition of Ar diluent. Grain sizes drop distinctly with the rise of the addition of Ar gas and laser power, but change little with the gas flow rate and reaction temperature. The formation of Si particles under different synthesis conditions is discussed
关键词:
Xinqing ZHAO
,
Yong LIANG
,
Keshen XIAO
,
Feng ZHENG and Zhuangqi HU (State Key Lab. of RSA
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
110015
,
China)(To whom correspondence should be addressed)
材料科学技术（英）
γ-Fe nano-particles with size of 20-40 nm were produced by SF6-sensitized CW CO2 laser-induced gaseous pyrolysis of Fe(Co) 5, The γ-Fe stabte in reaction zone at above 910℃ was formed.The rapid quenching prevents from the γ-Fe transforming to α-Fe as rapidly cooling from high temperature to room temperature, The characteristics of the particles were examined at room temperature by TEM. electron diffraction and XRD. It was proved that about 70% of γ-Fe phase in the particles was present. In addition. the lattice constant of the γ-Fe was 0.364 nm in place of 0.360 nm
关键词:
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
,
null
,
null
,
null
,
null
Yaling HAN
,
Quangang XIAN
,
Xibao WANG
,
Jialin LI
,
Yuqi JIANG
,
Yong LIANG
材料科学技术（英）
Al2O3/SiC nano composite ceramics can replace wear-resistant and heat-resistant alloys used in preparing the arm-bush that is the key parts in the equipment of galvanizing steel strip. Conventional alloy for arm-bush could only operate 4 similar to7 days, and the ceramic Arm-bush can operate more than 100 days continuously tested in the same equipment and its service life has increased 15 times more than that of alloy. According to the results of microstructure analysis, one of the most important cause that the composite ceramics possess excellent wear-resistant properties in the fused zinc is that nano SiC particles have existed within fine grains of Al2O3.
关键词:
