1996 Volume 45 Issue 11 Pages 1205-1210
To develop a material for single layer warm damper of superconducting generator, the influence of alloy elements such as Cu, Al, Ti, C and Zr on strength and toughness in precipitation hardening Ni-Cu-Al alloys was studied.
In Ni-11%Cu-4.3%Al type alloys, the combined addition of Ti and C decreases γ' particle diameter and distance between particles. 0.2% proof stress of the alloys is increased by the combined addtion of Ti and C.
In Ni-Cu-Al alloys, precipitation of γ' at grain boundaries is promoted by increasing Cu, Al, Ti and C. γ' at grain boudaries embrittles the alloys. In Ni-11%Cu-4.3%Al-0.4%Ti-0.15%C alloy, precipitation of γ' at grain boundaries is suppressed by adding a small amount of Zr and toughness of the alloy is improved.
An adequate composition of Ni-Cu-Al alloy for single layer warm damper is approximately Ni-11%Cu-4.0%Al-0.3%Ti-0.13%C-0.03%Zr in terms of mechanical and electromagnetic properties.
