http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
DV-Xα분자궤도법을 이용한 Zn alloy의 기계적 성질 예측
나혜성,공종판,김양수,강정윤,Na, H.S.,Kong, J.P.,Kim, Y.S.,Kang, C.Y. 한국재료학회 2007 한국재료학회지 Vol.17 No.5
The alloying effects on the electronic structures of Zinc are investigated using the relativistic $DV-X{\alpha}molecular$ orbital method in order to obtain useful information for alloy design. A new parameter which is the d obital energy level(Md) and the bonder order(Bo) of alloying elements in Zinc was introduced and used for prediction of the mechanical properties. The Md correlated with the atomic radius and the electronegativity of elements. The Bo is a measure of the strength of the covalent bond between M and X atoms. First-principles calculations of electronic structures were performed with a series of models composed of a MZn18 cluster and the electronic states were calculated by the discrete variational- $X{\alpha}method$ by using the program code SCAT. The central Zinc atom(M) in the cluster was replaced by various alloying elements. In this study energy level structures of pure Zinc and alloyed Zinc were calculated. From calculated results of energy level structures in MZn18 cluster, We found Md and Bo values for various elements of Zn. In this work, Md and Bo values correlated to the tensile strength for the Zn. These results will give some guide to design of zinc based alloys for high temperature applications and it is possible the excellent alloys design.
저Pb Sn-5%Pb-1.5%Ag=x%In계 솔더 합금의 특성에 관한 연구
강정윤,주철홍,홍순국,김인배 釜山大學校生産技術硏究所 1998 生産技術硏究所論文集 Vol.54 No.-
Pb의 환경오염 문제를 발생하지 않는 저농도 Pb 솔더합금을 개발하기 위하여, 새로운 Sn-5%Pb-1.5%Ag-x%In계 합금 조성을 설계하고, 이 합금의 융점, 젖음성, 상분석, 경도, 인장강도, 드로스성을 평가하여, Sn-37%Pb 솔더와 대체 가능성을 타진하였다. Sn-5%Pb 솔더 합금의 Pb이온 용출농도는 국제규제치인 2ppm¹)보다 훨씬 적은 0.46 ppm이었고, 환경문제를 유발하지 않는 것으로 확인되었다. 이 합금계의 융점은 183∼192℃이고, 응고온도범위도 5℃ 내외로 매우 좁았다. 젖음성은 In의 첨가량에 따라 큰 차이가 거의 없었으며, Sn-37%Pb와 비슷하였다. 융점 및 젖음성 측면에서 Sn-37%Pb와 대체 가능한 것으로 판단되었다. 경도는 Sn-37%Pb의 약 1.5배이고, 인장강도는 Sn-37%Pb의 것보다 높고, In의 첨가량에 따라 증가하였지만, 연신율은 감소 하였다. In이 1% 첨가된 합금에서는 수지상정 경계에 Ag₃Sn과 Pb가 정출되고, 3%이상에서는 Ag₃Sn과 Ag₃In 및 Pb가 정출되었다. 드로스 생성속도는 Sn-37%Pb합금이 Sn-5%Pb-1.5%Ag합금보다 빠르고, In을 첨가할수록 느리고, 2%의 In을 첨가한 합금은 180분에서도 거의 드로스가 발생하지 않았다. Recently environmental pollution caused by 'Pb' has posed a serious threat to the global environment, the trend to regulate the usage of 'Pb' in electronic industry is on the rise. Currently, the solder alloy with high Pb content, 63%Sn-37%Pb, is utilized in the electronic assembly; therefore, the objective of this study is to develop an alternative solder alloy for the existing 63%Sn-37%Pb solder alloy. First thing, this work choosed Sn-5Pb-1.5Ag, Sn-5Pb-1.5AgBi(x=1 ∼ 5%) for candidate solder alloys, and examined their properties such as melting range, wettability, microhardness, tensile property, oxidation behavior and microstructure. Wettability was on the same level of 63%Sn-37%Pb. Dissolution of Pb ion in 95%Sn-5%Pb solder was 0.46ppm. This solder alloy revealed cellular dendrite microstructure, β-Sn matrix, Pb-rich phase, Ag/Sn, and Cu/Sn Intermetallic compounds. The range of solidification temperature was within 30℃. Also these alloy displayed a higher U.T.S and lower elongation than 63%Sn-37%Pb. The resistance of oxidation in Sn-5Pb-1.5Ag solder alloy was superior to that of Sn-37Pb solder alloy. But that of Sn-5Pb-1.5Ag-5Bi solder alloy was equal to that of Sn-37%Pb solder alloy.