Wei GUO
,
Qingchang MENG
,
Jitai NIU
,
Xinmei ZHANG
材料科学技术（英文）
In this paper, a new method for welding SiCp/101A was put forward. It is LPI (liquid-phase-impacting) diffusion welding. Through LPI diffusion welding SiCp/101A aluminum, the effect of welding parameters on the welded joint property was investigated, and the optimal welding parameters were brought forward at the same time. The microstructure of joint was analyzed by means of optical-microscope, scanning electron microscope in order to study the relationship between the macro-properties of joint and the microstructure. The results show that LPI diffusion welding could be used for welding aluminum matrix composites SiCp/101A successfully.
关键词:
Aluminum matrix composite
,
null
,
null
Changli WANG
,
Zhimin WAN
,
Min ZHAO
,
Jitai NIU
材料科学技术（英文）
The fatigue properties of 2024T3 aluminum alloy welded joint treated by different peening methods were examined. The different effects on fatigue performance of high strength aluminum welded joints were compared with each other by carry out a series tests using two different peening treatment samples. Results show that by applying synchronized hammer peening to the weak part of joint when weld was going on, trailing peening, may refine the grains near weld line, hardening the surface of weld toe and amend the distribution of residual stress. Because of these results the position of fracture of joint was moved from weld toe to weld line. Compared to the joints treated by peening after welding, the fatigue strength of weld joint treated by trailing peening was enhanced by more than 102%.
关键词:
Fatigue strength
,
null
,
null
,
null
Lihong HAN
,
Jitai NIU
,
Darning JIANG
,
Tsunernichi Imai
材料科学技术（英文）
The superplasticity of an Al(2)O(3)p/6061Al composite, fabricated by powder metallurgy techniques, has been investigated. Instead of any special thermomechanical processing or hot rolling, simple hot extrusion has been employed to obtain a fine grained structure before superplastic testing. Superplastic tensile tests were performed at strain rates ranging from 10(-2) to 10(-4) s(-1) and at temperatures from 833 to 893 K. A maximum elongation of 200% was achieved at a temperature of 853 K and an initial strain rate of 1.67x10(-3) s(-1). The highest value obtained for the strain rate sensitivity index (m) was 0.32. Differential scanning calorimeter was used to ascertain the possibility of any partial melting in the vicinity of optimum superplastic temperature. These results suggested that no liquid phase existed where maximum elongation was achieved and deformation took place entirely in the solid state.
关键词:
Wei GUO
,
Jitai NIU
,
Jinfan ZHAI
,
Changli WANG
,
Jie YU
,
Guangtao ZHOU
材料科学技术（英文）
Through the vacuum diffusion bonding for SiCp/ZL101 aluminum matrix composite, the influence of bonding parameters on the joint properties was reported, with the aim to obtain optimal bonding parameters. The microstructure of joints was analyzed by means of optical microscope and scanning electron microscope in order to study the relationship between the macro-properties of joints and the microstructures. It was found that diffusion bonding could be used for bonding aluminum matrix composites successfully. Meanwhile, the properties of the matrix and the joint were all affected by some defects such as the reinforcement aggregation in aluminum matrix composites made by stirring casting.
关键词:
Aluminum matrix composite
,
null
,
null
,
null
