Z.Q. Wang1
,
2)
,
T.C. Ma2)
,
G.W. Liu2)
,
Y.J. Cai2) and B.L. Lu1) 1) College of Chemical Engineering
,
Dalian University of Technology
,
Dalian 116012
,
China
,
2) Department of Material Science and Engineering
,
Dalian Institute of LightIndustry
,
Dalian 116034
,
China
金属学报(英文版)
Based on thelow temperaturecombustion synthesisof α Al2 O3 from aluminum nitrate,the effectsofthe additives on the formation and particle properties of α Al2 O3 werestudied by XRDand SEM,theinitialstudy on the manometer α Al2 O3 synthesisby LCSwas done, α Al2 O3 withtheparticlesize50 ～80 NM wasgot under properconditions.
关键词:
low temperature combustion synthesis
,
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
Andrej Atrens
材料科学技术（英文）
Corrosion research by Atrens and co-workers has made significant contributions to the understanding of the service performance of engineering materials. This includes: (1) elucidated corrosion mechanisms of Mg alloys, stainless steels and Cu alloys, (2) developed an improved understanding of passivity in stainless steels and binary alloys such as Fe-Cr, Ni-Cr, Co-Cr, Fe-Ti, and Fe-Si, (3) developed an improved understanding of the melt spinning of Cu alloys, and (4) elucidated mechanisms of environment assisted fracture (EAF) of steels and Zr alloys. This paper summarises contributions in the following: (1) intergranular stress corrosion cracking of pipeline steels, (2) atmospheric corrosion and patination of Cu, (3) corrosion of Mg alloys, and (4) transgranular stress corrosion cracking of rock bolts.
关键词:
Stress corrosion cracking
,
null
,
null
Acta Materialia
The oxidation behavior of Ti3SiC2-based material in air has been studied from 900 degreesC to 1200 degreesC. The present work showed that the growth of the oxide scale on Ti3SiC2-based material obeyed a parabolic law from 900 degreesC to 1100 degreesC, while at 1200 degreesC it followed a linear rule. The oxide scale was generally composed of an outer layer of coarse-grained TiO2 (rutile) and an inner layer of fine-grained TiO2 and SiO2 (tridymite) above 1000 degreesC, A discontinuous coarse-grained SiO2 layer was observed within the outer coarse-grained TiO2 layer on the samples oxidized at 1100 degreesC and 1200 degreesC. Marker experiments showed that the oxidation process was controlled by the inward diffusion of oxygen. outward diffusion of titanium and CO or SiO, and that internal oxidation predominated. The TiC content in Ti3SiC2 was deleterious to the oxidation resistance of Ti3SiC2. (C) 2001 Acta Materialia Inc. published by Elsevier Science Ltd. All rights reserved.
关键词:
Ti3SiC2-based material;oxidation;titanium-silicon carbide;alloys
材料科学技术（英文）
The wear and friction properties of Ti3SiC2-based materials were studied using the pin-on-disc method. The friction coefficient of Ti3SiC2-based material was not very sensitive to normal load, the steady state value, p, increased from 0.4 to 0.5 when the normal load increased from 7.7 N to 14.7 N. The wear volume for Ti3SiC2 disc increased with increasing normal load or sliding distance in the tests. The average wear rate of Ti3SiC2-based material was 9.9X10(-5) mm(3)/Nm. The debris on the Ti3SiC2 disc was essentially made up of Ti3SiC2 and steel pin materials, while the debris on the steel sliders was generally pip material. The wear mechanism was concluded as the fracture and delamination of Ti3SiC2-based materials followed by adhesive wear of steel sliders.
关键词:
Ti3SiC2;wear and friction;friction coefficient;wear volume;titanium-silicon carbide;friction
Science
Strengthening materials traditionally involves the controlled creation of internal defects and boundaries so as to obstruct dislocation motion. Such strategies invariably compromise ductility, the ability of the material to deform, stretch, or change shape permanently without breaking. Here, we outline an approach to optimize strength and ductility by identifying three essential structural characteristics for boundaries: coherency with surrounding matrix, thermal and mechanical stability, and smallest feature size finer than 100 nanometers. We assess current understanding of strengthening and propose a methodology for engineering coherent, nanoscale internal boundaries, specifically those involving nanoscale twin boundaries. Additionally, we discuss perspectives on strengthening and preserving ductility, along with potential applications for improving failure tolerance, electrical conductivity, and resistance to electromigration.
关键词:
strain-rate sensitivity;stacking-fault energy;nano-scale twins;cu-al;alloys;nanocrystalline metals;mechanical-properties;activation;volume;copper;deformation;behavior
Materials Research Innovations
Cu/Ti3SiC2 composite, a new electrofriction material, was prepared, for the first time, by PM method. The microstructure, mechanical and electrical properties of the Cu/Ti3SiC2 composites were investigated and were compared with those of Cu/graphite composites. The results demonstrated that Cu/Ti3SiC2 composites had superior mechanical properties over Cu/graphite composites. At filer content of less than 20 vol%, the electrical conductivity for Cu/Ti3SiC2 composites was higher than that for Cu/graphite composites; at high filer content, the electrical conductivity for Cu/Ti3SiC2 composites was lower than that for Cu/graphite composites because of the presence of residual pores. It was found that like Cu/graphite composite, Cu/Ti3SiC2 was a self-lubricated material. The compressive yield strength, Brinell hardness, relative ratio of compressive for Cu-30 vol% Ti3SiC2 composites are 307 MPa, 140, 15.7% respectively.
关键词:
electronfriction material;copper;Ti3SiC2;graphite;composite;self-lubricating;ti3sic2
