AGEING EFFECT ON STRUCTURE AND PROPERTIES OF HIGH-STRENGTH AND HIGH-CONDUCTIVE COPPER ALLOYS

摘要

Cu-Cr-Zr-alloy with Cr and Zr micro-additives was manufactured via semi-continuous casting from induction furnace. After homogenization at 880 deg C during 12 hours, the ingots have been extruded at the horizontal 8 MN press (with elongation ratio equals 16) for shapes 25 X 7 mm, which have been subsequently quenched in a water. Afterwards the shape was subjected to cold deformation with deformation degree as much as 50 percent, and to ageing via different conditions, with measuring mechanical and electrical properties of the alloy. It was shown that cold-drawn shape, having been annealed at 450 deg C during 4 hours, increased its tensile strength and yield strength up to 465 MPa and 380 MPa, and raised its relative elongation and electric conductivity up to 16 percent and 80 IAGS correspondingly. The results of micro-structural analysis displayed that increase of tensile strength of the alloy is explained mainly by separation of Cr and Cu_3Zr caused by alloying with Cr and Zr micro-additives, and high electric conductivity of the alloy is connected mainly with depletion of copper matrix of the solid solution (whose composition is going to be close to clear copper).