Softening Resistant Copper Alloy, Preparation Method, and Application Thereof

Abstract

A softening resistant copper alloy, a preparation method, and an application thereof, the softening-resistant copper alloy, comprising 0.1%-1.0 wt % Cr, 0.01%-0.2 wt % Zr, 0.01%-0.10 wt % Si, and ≤0.10 wt % Fe, and with the remaining of copper and inevitable impurities, wherein the microstructure of the copper alloy contains comprises: an elemental Cr phase, a Cu5Zr phase, and a Cr3Si phase. In the copper alloy of the present invention, the high-temperature softening resistance effect of the material is improved by adding a proper amount of Si to form a compound Cr3Si, and the strength and the high-temperature softening resistance of the material are further improved by strengthening the copper alloy matrix by the elemental Cr phase and the Cu5Zr phase, using the synergistic effect of the Cr3Si phase and the elemental Cr phase and by controlling the content of the impurity Fe. The copper alloy can be applied to contact lines and welding materials to prolong the service life of the materials.

1 . A softening-resistant copper alloy, comprising:
 0.1%-1.0 wt % Cr,   0.01% -0.2 wt % Zr,   0.01%-0.10 wt % Si, and   ≤0.10 wt % Fe, and   with the remaining of copper and inevitable impurities,   wherein the microstructure of the copper alloy comprises:   an elemental Cr phase,   a Cu 5 Zr phase, and   a Cr 3 Si phase.   
     
     
         2 . The copper alloy of  claim 1 , wherein the elemental Cr phase and the Cr 3 Si phase satisfy the following relationship:
 if the weight of the elemental Cr phase is X and the weight of the Cr 3 Si phase is Y, then 0<X/Y<20.   
     
     
         3 . The copper alloy of  claim 1 , further comprising: 0.0001%-0.10 wt % Mg. 
     
     
         4 . The copper alloy of  claim 1 , further comprising: 0.01% to 2.5 wt % of any one or more of Co, Zn, Mn, Sn and Nb, and their total amount does not exceed 3.5 wt % of the copper alloy. 
     
     
         5 . The copper alloy of  claim 1 , wherein the softening temperature of the copper alloy is greater than or equal to 580° C. 
     
     
         6 . A method for preparing the copper alloy of  claim 1 , the method comprising:
 alloying and refining—casting into an ingot—ingot sawing, heating and extruding—solid solution heat treatment—stretching and drawing—aging heat treatment—straightening and finalizing;   wherein the casting temperature for the alloying treatment and the covered refining is 1150° C. to 1350° C.; the temperature for the hot extrusion is 850° C. to 950° C.; the temperature for the solid solution treatment is 850° C. to 1000° C.; the cooling medium is water, and the cooling rate is 10° C./min to 150° C./s; the machining rate of the cold stretching and drawing is 20% to 60%; the temperature for the aging heat treatment is 420° C. to 520° C.; and, the copper alloy is insulated for 2 h to 4 h.   
     
     
         7 . The copper alloy of  claim 1 , the method comprising using the softening-resistant copper alloy in contact lines and welding materials.