Study of Texture Analysis on Asymmetric Cryorolled and Annealed CoCrNi Medium Entropy Alloy

CoCrNi equiatomic medium entropy alloy sheets were prepared by asymmetric rolling, cryorolling, and asymmetric cryorolling. The asymmetric cryorolled samples exhibited a noteworthy ultra-fine-grain heterogeneous lamella structure. The microstructure and corresponding hardness obtained by different rolling processes and subsequent annealing are compared. It can be seen from the results that the cryogenic deformation temperature had a stronger effect on the mechanical properties of the medium entropy alloys (MEA), compared with the shear strain caused by the asymmetric cryorolling. The effect of annealing temperature on texture components and volume fractions of the specially rolled samples was also analyzed. The result revealed that the recrystallized MEA exhibited similar texture components and the corresponding volume fraction, which indicated that the rolling process had limited influence on the formation of annealing texture. The recrystallized texture after annealing retained the deformation texture and twin related orientations appeared. Asymmetric rolled MEA showed strong random composition than symmetric rolled MEA regardless of rolling temperature. The recrystallized textures of the species obtained by the three rolling processes did not exhibit a significant dependence on the annealing temperature.

Influence of Manganese on the Recrystallization Characteristics and Texture Development of Cu-29Zn Alloys

Studies regarding the recrystallization texture of brass alloys are quite complex. Previous experiments showed that the addition of the alloying elements on brass alloys affect the deformation mechanism and texture development. Alloying elements promoted the inhomogeneous deformation and resulted in a heterogeneous microstructure. During annealing, the new grains form around the shear band area and develop the random texture. This research studied the effect of Mn addition on the recrystallization characteristics and texture development of Cu-29Zn alloys. The Cu-Zn-xMn alloys were produced by gravity casting with a dimension of 110x110x6 mm3. The feeding material includes pure Cu, Zn, and Mn. The as-homogenized samples were then cold-rolled with the level of deformation of 70 % and followed by an annealing process at temperatures of 400, 500, and 600°C. Samples characterization includes chemical composition analysis, microstructure observation, hardness testing, and texture measurement. The results showed that the addition of Mn tended to reduce the rate of recrystallization and grain growth. At 70% deformation, Mn addition promoted the formation of brass and Goss texture. The presence of Mn also influenced the formation of recrystallization and annealing texture.