Hot working of aluminum alloy 7075
Large deformation, constant true strain rate, isothermal compression tests have been conducted on the aluminum alloy 7075 at strain rates which ranged from 103 to 1 sec1 and temperatures which spanned the practical forging temperature range of 3250C 4250 C. In this strain rate and temperature regime the stress-strain curves show very little strain hardening or softening, and the relationship between the (visco) plastic strain rate iP, the absolute temperature T, and the flow stress a can be represented well by the classical one-dimensional equation:
Flow Stress Determination for Metals at Forging Rates and Temperatures
In this study, the uniform compression test is used to determine the flow stress of 403 stainless steel, Waspaloy, Ti-6Al-2Sn-4Zr-2Mo, Inconel 718, Ti-8Mo-8V-2Fe-3Al, and, AISI 4340 at various forging temperatures. The ring-compression test is used to determine the flow stress of 6061 aluminum, Ti-7Al-4Mo, 403 stainless steel, Waspaloy, 17-7 PH stainless steel, Ti-6Al-4V, Inconel 718, Ti-8Al-1Mo-V, 7075 aluminum, and Udimet 700 alloy at forging temperatures. All the tests were conducted, at practical deformation rates encountered in forging, on an instrumented high-speed forging press. For the same material and at similar temperature and deformation-rate conditions, the data obtained from the uniform-compression and ring-compression tests were compared. It was found that the results obtained with rings 3-in. O.D., 1.5-in. ID and 1 in. high were practically identical to those obtained from the isothermal uniform-compression tests conducted with samples 1-in. dia and 1.5 in. high.
Self-assembly of pyridinium-tailored anthracene amphiphiles into supramolecular hydrogels.
The mixing of a polyacid cross-linker with a pyridinium-functionalized anthracene amphiphile afforded a supramolecular hydrogel through a self-assembly process that was primarily driven by π-stacking and electrostatic interactions.