Superplastic zinc

Zinc rolling slabs have been cast successfully by semicontinuous direct-chill casting methods. This is the preferred method for superplastic zinc alloys which, because of their large freezing range, display unacceptable surface shrinkage when cast in open molds. 

It exhibits superplasticity. Neither zinc nor zirconium is ferromagnetic but ZrZnz exhibits... 

Another commercial development of the 1970s is the appHcation of superplasticity which is exhibited by a number of zinc alloys (135—138). Under the right conditions, the material becomes exceptionally soft and ductile and, under low stresses, extensions exceeding 1000% can be obtained without fracture. The grain size must be extremely small (about 1 micrometer) and stable. This grain size is less than one tenth that of common metals in the wrought condition. 

C M. Packer. R.H. Johnson, O.D Sherby, "Evidence for the importance of crystal- lo-graphic slip during superplastic deformation of eutectic Zinc - Aluminium". Trans.Met.Soc. AIME242, 2485, 1968... 

Superplastic Meta Manual, The New Jersey Zinc Company, Palmerton, Pa., 1970. 

Al—Zn, Aluminum-rich binary alloys (Fig. 18) are not age hardenable to any commercial significance, and zinc [7440-66-6], Zn, additions do not significantly increase the abiHty of aluminum to strain harden. Al—Zn alloys find commercial use as sacrificial claddings on high strength Al—Cu—Mg—Zn aircraft ahoy sheet. The eutectoid composition near 78% Zn has found use as a superplastic sheet alloy. 

Zinc is a bluish-white, lustrous metal. It is brittle at ordinary temperatures, but malleable at 100 to 150°C. It is a fair conductor of electricity, and bums in air at high red heat, with evolution of white clouds of the oxide. It exhibits superplasticity. 

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