Effect of Heat Treatment on Microstructure and Properties of CuNiTiBe Alloy

The performance of CuNiTiBe alloy produced under different heat processing technological conditions had been studied.The best technological parameters had been determined by performance test.The strengthening mechanison had been analyzed using optical microscope and transmission electron microscope.The results indicate that the best match between the mechanical properties and electrical performance existed when the alloy was treated by such technology as 940 ℃×1 h(water quenching) solid solution ＋480 ℃×2 h aging and got following properties conductivity of 17.4×10-6 S·m-1,hardness of 270 HV,softening temperature of 670 ℃,average grain size ≤3 μm and large quantity of twin existed in the microstructure.The strengthening phase Be2Cu and the matrix had the relationship of coherence.And two shapes of strengthening phase Ni3Ti and Be2Cu distributed in the matrix of the alloy.One was the dispersed equiaxed nano-particles.Another was the micron dimension strengthening phase mixed by a variety of geometric patterns.The performance index of strength and hardness and the capability of resistance to high-temperature increased by the combined action of fine-grains,twins and strengthening phases.