S.H.Liang and Z.K.Fan The Department of Material and Engineering
,
Xi'an University of Technology
,
Xi'an 710048
,
China
金属学报(英文版)
A kind of Cu base composite reinforced by 0 1μm Al 2O 3 particles were prepared by hot pressing and sintering process for steel continuous casting mould. The microstructure and properties were studied. The results show that the Al 2O 3 particle distribution is uniform, and the particles refine the grain size. The tensile fracture is a mixture of quasi cleavage and dimple due to the moderate interface strength. As a result, the composite has better soft resistance and wear resistance than those of Cu and Cu alloy. With increase in super fine Al 2O 3, the density and electric conductivity of the composite decrease, but hardness and strength increase.
关键词:
hot pressing and sintering
,
null
,
null
,
null
Fang Geng
材料科学技术（英文）
Three-dimensional honeycomb-structured magnesium (Mg) scaffolds with interconnected pores of accurately
controlled pore size and porosity were fabricated by laser perforation technique. Biodegradable and bioactive β-
tricalcium phosphate (β-TCP) coatings were prepared on the porous Mg to further improve its biocompatibility,
and the biodegradation mechanism was simply evaluated in vitro. It was found that the mechanical properties
of this type of porous Mg significantly depended on its porosity. Elastic modulus and compressive strength
similar to human bones could be obtained for the porous Mg with porosity of 42.6%-51%. It was observed
that the human osteosarcoma cells (UMR106) were well adhered and proliferated on the surface of the β-
TCP coated porous Mg, which indicates that the β-TCP coated porous Mg is promising to be a bone tissue
engineering scaffold material.
关键词:
Magnesium
,
Bone tissue engineering
,
β-TCP coating
,
Biocompatibility
材料科学技术（英文）
Three-dimensional honeycomb-structured magnesium (Mg) scaffolds with interconnected pores of accurately controlled pore size and porosity were fabricated by laser perforation technique. Biodegradable and bioactive beta-tricalcium phosphate (beta-TCP) coatings were prepared on the porous Mg to further improve its biocompatibility, and the biodegradation mechanism was simply evaluated in vitro. It was found that the mechanical properties of this type of porous Mg significantly depended on its porosity. Elastic modulus and compressive strength similar to human bones could be obtained for the porous Mg with porosity of 42.6%-51%. It was observed that the human osteosarcoma cells (UMR106) were well adhered and proliferated on the surface of the beta-TCP coated porous Mg, which indicates that the beta-TCP coated porous Mg is promising to be a bone tissue engineering scaffold material.
关键词:
Magnesium;Bone tissue engineering;beta-TCP coating;Biocompatibility;simulated body-fluid;mechanical-properties;cancellous bone;foam;scaffolds;magnesium;hydroxyapatite;porosity;bioceramics;fabrication;ph
唐波
,
朱丽慧
机械工程材料
利用RD-2型高温持久试验机、高分辨透射电子显微镜和能谱仪研究了国产S30432耐热钢在供货态及不同温度、应力条件下持久断裂后的第二相,尤其是Z相的析出行为及影响因素.结果表明:供货态S30432钢中只存在MX相;在650℃、170 MPa、10 712 h持久条件下析出了M23 C6碳化物和富铜相;在700℃、150MPa、937 h条件下,不仅析出了M23 C6碳化物和富铜相,还出现了Z相及包含MX相和Z相的颗粒;在700℃、150 MPa、1 944 h条件下Z相粗化缓慢,在700℃、100MPa、11 832 h条件下Z相粗化明显;高温和应力均会加速Z相的析出.
关键词:
耐热钢
,
Z相
,
显微组织
陈立志
,
张亚军
材料开发与应用
doi:10.3969/j.issn.1003-1545.2011.05.010
分别采用三点弯曲SE(B)与紧凑拉伸C(T)试样,通过-20℃的低温裂纹尖端张开位移CTOD断裂韧性试验及疲劳裂纹扩展速率da/dN试验,研究了S355N及S355N-Z25结构钢的裂纹启裂与扩展的抗力.研究结果表明:S355N钢抵抗裂纹启裂及前期扩展的能力比S355N-Z25钢强,但前者抵抗裂纹后期扩展的能力比后者弱；当应力强度因子范围,△K小于34.3MPa·√m时,S355N钢的疲劳抗力比S355N-Z25钢弱,当△K等于34.3MPa·√m时,两者具有相同的疲劳抗力,当△K大于34.3MPa·√m时,前者的疲劳抗力比后者强.研究结果对两种钢板在工程上应用及结构的安全评定提供了参考.
关键词:
S355N及S355N-Z25钢板
,
低温CTOD断裂韧性
,
疲劳裂纹扩展速率da/dN
,
裂纹启裂
,
裂纹扩展
,
抗力
窦强
,
王斌
高分子材料科学与工程
研究了β晶型成核剂(酰胺化合物)成核改性纤维级聚丙烯Z30S的力学性能,进行了广角X射线衍射和DSC分析.发现成核改性后生成了β晶型聚丙烯,因而聚丙烯Z30S的冲击性能提高.通过纺丝-拉伸实验和对纤维进行广角X射线衍射分析、SEM观察,发现成核改性纤维在纺丝拉伸过程中发生了晶型转变,产生大量微孔隙.
关键词:
聚丙烯
,
β晶型
,
成核剂
,
纤维
Intermetallics
The sulfidation behavior of a 200 mum thick Fe-40at.%Al sheet has been investigated at temperatures between 973 K and 1273 K in H-2-H2S mixtures with H,S contents of 0.052-9.7vol%. The Fe-40Al sheet exhibited excellent sulfidation resistance at temperatures below 1073 K in all the H2S-H-2 mixtures. This may be attributed to the formation of a thin alumina film on the surface of the Fe-40Al sheet during sulfidation, identified by AES analysis. At temperatures higher than 1173 K, the Fe-40Al sheet also exhibited good sulfidation resistance in the 0.052%H2S-H-2, mixture. and there was only a slight increase in mass gain with tempe rat Lire. This compares favorably with Fe-200-11Al (in at.%) foil which was severely sulfidized even at 973 K in the 0.052% H2S-H-2 mixture, and showed markedly increased mass gain with increased H2S content and temperature. (C) 2004 Elsevier Ltd. All rights reserved.
关键词:
iron aluminides (based on FeAl);corrosion;fe-al alloys;corrosion behavior;oxidation behavior;iron aluminides;sulfur vapor;al2o3 scales;1273 k;atmospheres
程俊梅
,
张萍
,
于广水
,
赵树高
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2009.06.016
在比表面积相近的情况下,探讨白炭黑(Z125)及碳黑(N234)对天然橡胶(NR)和溶聚丁苯橡胶(S-SBR)硫化胶的抗割口增长能力及动态力学性能的影响.结果表明,Z125和N234对NR和S-SBR两种硫化胶的增强效果相差不大;NR硫化胶的抗割口增长能力明显好于S-SBR硫化胶;NR中填充Z125的抗割口增长能力好于N234且随疲劳次数的增加Z125的优势更加明显,而S-SBR中填充N234的抗割口增长能力好于Z125且两者的抗割口增长速率基本不随疲劳次数的增加而改变;Z125使NR和S-SBR硫化胶在0℃和70℃下的tanδ值分别低于N234增强相应硫化胶.
关键词:
NR
,
S-SBR
,
白炭黑
,
炭黑
,
动态力学性能
,
抗割口增长能力
