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Effect of Rare Earths on Solidification Microstructure and High Temperature Mechanical Property of Sn60-Pb40 Solder alloy

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Journal of Rare Earths 2000年第4期18卷 289-292页

作者：马鑫钱乙余 Harbin Inst Technol Natl Key Lab Welding Harbin 150001 Peoples R China natl key lab reliabil phys elect prod Guangzhou 510610 Peoples R China Hiroshima Univ Dept Mech Engn Higashihiroshima 724 Japan

Trace rare earth elements were used in order to strengthen the Sn60 Pb40 solder alloy. The experimental results show that the high temperature tensile strength of near eutectic Sn60 Pb40 solder alloy is increased by about 70% after adding trace rare earth elements. Analysis shows that the high affinity between rare earth element and Sn leads to the variation of contact angle at the three phase junction of S/L interface during eutectic growth and further changes the Pb concentration at the S/L interface needed for coupled eutectic growth. Thus the eutectic microstructure can directly grow upon the primary Pb rich phase and the formation of coarse Sn rich halo is suppressed. Therefore homogeneous metallurgical microstructure can be obtained.

关键词： rare earths high temperature tensile strength eutectic growth microstructure

Thermodynamic Assessment of Interaction Relation between Lanthanum and Constituent Elements in Sn-Pb Alloy

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Journal of Rare Earths 2001年第2期19卷 107-109页

作者：薛松柏马鑫钱乙余 Harbin Inst Technol Natl Key Lab Welding Harbin 150001 Peoples R China Minist Informat Ind Natl Key Lab Reliabil Phys Elect Prod Guangzhou 510610 Peoples R China Hiroshima Univ Dept Mech Engn Hiroshima 739 Japan

The interaction relation between lanthanum and the constituent elements of Sn-Pb alloy system was analyzed by using the thermodynamic models including Miedema formation energy model for binary system, Tanaka modification by excess entropy and the Chou geometric model for ternary system. The thermodynamic calculaton results show that lanthanum has higher affinity for Sn in the Sn-Pb system. This is an important foundation for the improvement of the metallurgical properties of Sn-Pb solder alloy by adding rare earth elements.

关键词： rare earths lanthanum Sn-Pb alloy interaction thermodynamic

Finite element simulation for mechanical response of surface mounted solder joints under different temperature cycling

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中国有色金属学会会刊：英文版 2001年第4期11卷 471-474页

作者：马鑫钱乙余 Harbin Inst Technol Natl Key Lab Welding Harbin 150001 Peoples R China elect prod reliabil & Environm Testing Res Inst Res & Anal Ctr Guangzhou 510610 Peoples R China Hiroshima Univ Dept Mech Engn Higashihiroshima 739 Japan

Nonlinear finite element simulation for mechanical response of surface mounted solder joint under different temperature cycling was carried out. Seven sets of parameters were used in order to evaluate the influence of temperature cycling profile parameters. The results show that temperature cycling history has significant effect on the stress response of the solder joint. Based on the concept of relative damage stress proposed by the authors, it is found that enough high temperature holding time is necessary for designing the temperature cycling profile in accelerated thermal fatigue test.

关键词： finite element simulation surface mounted solder joint thermal cycling mechanical response

Effect of Yttrium Pre-Implantation on Implantation Behavior of Ti-6Al-4V Alloy in Nitrogen Plasma Immersion Ion Implantation

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Journal of Rare Earths 2001年第1期19卷 40-43页

作者：王浪平唐保茵王小锋王松岩 Harbin Inst Technol Natl Key Lab Adv Welding Prod & Technol Harbin 150001 Peoples R China City Univ Hong Kong Dept Phys & Mat Sci Kowloon Hong Kong Peoples R China

In order to increase the peak depth of nitrogen atoms during the nitrogen plasma immersion ion implantation of Ti-6Al-4V alloy, the rare earth metal yttrium was applied. In the experiment, yttrium and nitrogen ions were implanted under the voltage of 20 and 30 kV, respectively. In the samples with yttrium pre-implantation for 30 min, the Anger electron spectroscopy (AES) analysis shows that the peak depth of the nitrogen atoms increases from 50 up to 100 nm. It can also be seen from the tribological tests that the wear resistance of these samples is increased remarkably.

关键词： rare earths yttrium plasma immersion ion implantation peak depth

Measurement　of　Concentration　Distribution　of　electrogenerated　Etchant　Using　an　electrochemical　Probe　Technique

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Chinese Chemical Letters 1996年第9期7卷 835-836页

作者： Lian Yong SU Jin LUO Zhong Hua LIN Zhao Wu TIAN(National lab of Molecular and Biomolecular electronics,Southeast University,Nanjing 210018)(State key lab for physical Chemistry of Solid Surfaces,Department of Chemistry,Xiamen University 361005) SE UNIV NATL LAB MOL & BIOMOL ELECTNANJING 210018PEOPLES R CHINA XIAMEN UNIV DEPT CHEMSTATE KEY LAB PHYS CHEM SOLID SURFACESXIAMEN 361005PEOPLES R CHINA

An electrochemical probe measurement system for detecting an electrogenerated etchant in solution is *** distribution of electrogenerated etchant bromine as close as 8 micrometer to the surface of macrodisk is studied... 详细信息

关键词： Measurement electrochemical Probe Technique Concentration Distribution