THE CAVITY DURING SUPERPLASTIC DEFORMA-TION & ITS INFLUENCE ON MECHANICALPROPERTIES OF SUPERPLASTICALLY-DEFORMED MATERIALS AT RT
DuZhixiao; WuShichun; Heyongmei(Northwestern Polylechnical University, Xi'an, China, 710072)
The cavity during superplastic deformation for the half-hardened brassH62 and the alluminium alloy LY12CZ without any pre-treatment and its influence onthe mechanical properties of the superplastically-defonned matenals at room tempera-ture have been investigated. The expenmental results show that (1) for the same mate-rial, superplastically-deformed under different conditions, the slower the rate ofcavitation as the strain increases, the higher the superplasticity is, (2) the mechanicalproperties of superplastically-deformed matenals at room temperature decrease as thesuperplastically-deformed strain increases, i.e.. a noteworthy decrease in elasticitymodulus E. yield strength δs, ultimate strength δb andnotch toughness ak at roomtemperature begins to appear as the area fraction of cavities comes up to about 4%,while at the same level the reduction in area drops down a very large quantity, (3) asthe level of cavitation increases in degrees, the superplastically-deformed materialchanges from ductile to brittle gradually.
【CateGory Index】： V211