Study On Valent Electron Structure And Properties Of CuCrSnZn Alloy

Cu-0.38Cr-0.17Sn-0.16Zn alloy is a kind of aging strengthened alloy. Because ofits high strength and electrical conductivity, it is used for lead frame in large scaleintegrated circuit.The papers studied the effect of cold deformation and aging parameters on theproperties of Cu-0.38Cr-0.17Sn-0.16Zn alloy. The result shows that after solution at920℃for1h, the alloy aged at450℃can obtain higher micro-hardness, while aged at550℃it can acquire higher conductivity. And the properties of the copper alloy willbe increased with60%cold deformation before aging. On the basis of theseexperimental results, the comprehensive aging techniques of Cu-0.38Cr-0.17Sn-0.16Zn alloy are proposed. Six kinds of the comprehensive aging techniques were tried.With the process “920℃×1h solution treatment�'60%cold-deformation�'450℃×3haging�'60%cold-deformation�'450℃×1h aging�'40%rolling”, the higher micro-hardness(172HV) and conductivity(72.4%IACS) can be obtained.Based on the solid and molecular experience electronic theory (EET), the modelsand methods to calculate the valence electron structures (VES)and the interfaces inCu-0.38Cr-0.17Sn-0.16Zn alloy were introduced and established. By using thesemodels，the relationships between the solid solution strengthening and VES ofdifferent phases, and between the precipitation strengthening and VES of differentinterfaces are discussed systematically. The results show the strength of the interactionbetween solute atoms and dislocation can be attributed by the value of nA. The strengthof the interaction between the misfit stress field of interface and the movingdislocation can be attributed by the value of. The larger the, the greater theinterfacial stress, the stronger the resistance to dislocation motion, the higher thestrength of the alloy. Based on the relationship of the electron structure parameterswith the solid solution strengthening, interface strengenthing and precipitationstrengthening, a model to calculate the strength of high strength high conductivity copper alloy was established. The calculated results are consistent with the actualvalue, which indicates that it is a feasible method to calculate the copper mechanicalproperties, and it’s a good way to predict the copper alloy’s composition.