LIANG Yong ZENG Xiaoyan TONG Baiyun SI Zhongyao Institute of Metal Research
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Academia Sinica
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Shenyang
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China LIANG Yong
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Professor
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Institute of Metal Research.Academia Sinica
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Shenyang 110015
,
China
金属学报(英文版)
The effect of the laser processing parameters on the composition uniformity and shape coefficient of fusion zone with laser surface alloyed Cr plated on medium carbon low alloy steel has been studied.It was found that the composition uniformity depends on the shape coefficient of fusion zone,and the later is a function of both power density and interaction time.If the power density is fixed to a certain value,the shape coefficient is directly,propor- tional to the interaction time.A completely,uniform molten pool can be obtained,when the shape coefficient is between 1.6 and 3.0.
关键词:
laser alloying
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null
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Daolun CHEN B.Weiss R.Stickler University of Vienna
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Wahringer Street 42
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A-1090 Vienna
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AustriaZhongguang WANG State Key Laboratory for Fatigue and Fracture of Materials
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Institute of Metal Research.Academia Sinica
,
Shenyang 110015
,
China
材料科学技术（英文）
Near-threshold fatigue crack propagation behaviour of a cold-worked copper tested with distinct fa- tigue testing systems under different stress ratios has been investigated.The emphasis was placed on the evaluation of crack closure effect as well as the effective fatigue threshold,It was found that the fatigue threshold for R=0 is higher than those for R=-1 and R=0.4,for which almost the same threshold value was derived.Compared with the conventional closure evaluation method,the pro- posed new closure evaluation method can generally interpret the dependence of the fatigue thresh- old on stress ratio and loading condition,and leads to a higher and relatively constant effective fa- tigue threshold of about 3 MPa·m~(1/2) for the cold-worked copper at different stress ratios and loading conditions.
关键词:
near-threshold fatigue
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null
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