Significant Enhancement in Cryogenic Mechanical Properties of Cu–Al Alloy via Minor Recrystallization

Abstract

The mechanical properties of cold-rolled (CR) and partially recrystallized (PRX) Cu-Al alloy are investigated by tensile tests at 77 and 293 K. While the uniform elongation is limited for the CR specimens at both temperatures, uniform elongation is enhanced unprecedentedly from 2.4% at 293 K to 16.5% at 77 K for the PRX specimens. In contrast to the sole contribution of recrystallized grains via wavy slip at 293 K, the prominent uniform elongation at 77 K is attributed to the multiple deformation mechanisms within recrystallized grains and the harmonization of plastic deformation between recrystallized grains and matrix.

Regional Control and Optimization of Heat Input during CMT by Wire Arc Additive Manufacturing: Modeling and Microstructure Effects

“…The temperature of the specimen remains at the recrystallization temperature for a period of time when the specimen is affected by repeated heat during the deposition process, and the new grains grow up and gradually replace the original grains grown by thermal effect. The sequence of recrystallization involves the disappearance of adjacent subgrains and the combination of subgrains, and this process does not affect the crystal structure of grains [ 16 , 17 ]. Compared with the other two processes, the controlled heat input process (Specimen D) has a shorter test time and lower temperature, so it produces the fewest coarse recrystallized grains, along with a smaller average grain size and more uniform grain size.…”