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228031 
Journal Article 
Phase transformation in Cu-Cr-Zr-Mg alloy 
Su, J; Liu, P; Li, H; Ren, F; Dong, Q 
2007 
1 
Materials Letters
ISSN: 0167-577X
EISSN: 1873-4979 
61 
27 
4963-4966 
English 
After solid solution treatment, the effects of aging processes on the microstructure and electrical conductivity of Cu-Cr-Zr-Mg lead frame alloy were investigated in order to determine the phase transformation and the time-temperature-transformation (TTT) behavior. The results show that aged at 470 deg C the fine precipitation of an ordered CrCu2(Zr,Mg) phase is found in copper matrix as well as fine Cr and Cu4Zr, aged at 550 deg C the phase CrCu2(Zr,Mg) is decomposed into Cu4Zr and Cr phase, aged at 600 deg C the precipitates is bcc Cr only. The phase transformation kinetics equation was deduced from the Avrami empirical formula based on the linear relationship between the electrical conductivity and the volume fraction of the phase transformation. 
Phase transformations; Copper base alloys; Precipitation; Electrical; conductivity; Precipitates; Volume fraction; Microstructure; TTT; curves; Lead frames; Body centered cubic lattice; Decomposition; Kinetic equations; Aging; COPPER ALLOYS (40 TO 99.3 CU); CHROMIUM; ALLOYS (0 TO 2 CR); CHROMIUM ALLOYS (2 TO 50 CR); ZIRCONIUM ALLOYS (0; TO 0.5 ZR); ZIRCONIUM ALLOYS (0.5 TO 50 ZR); MAGNESIUM ALLOYS (0 TO 50; MG); 11 Constitution (MD); G1 General and Nonclassified (EC); G1 General; and Nonclassified (ED); G1 General and Nonclassified (EP); 7 Physical; Metallurgy (CD)