Effect of Static Electropulsing on Microstructure and Elongation of a Zn-Al Alloy (ZA22)

Abstract

YAOHUA ZHU, SUET TO, XIANMING LIU, and GUOLIANG HUThe effects of static electropulsing on the phase transformations and elongation of a colddeformed Zn-Al based alloy wire (ZA22) were studied using scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD) techniques. Based on the transmission electron microscopy (TEM) determined lattice parameters of the phases involved, the electropulsing induced circular phase transformations were detected in the alloys using EBSD, which were never reported in any thermal and thermomechanical treated alloys. An adequate static electropulsing favored improving the identities of dislocation and microstructures (including the precipitation of the second phase, the residual stress, etc.), which resulted in enhancement of the plastic elongation of the alloy.

Constitutive modeling for hot deformation behavior of ZA27 alloy

“…A fourthorder polynomial, as shown in Eq. (9), was found to represent the influence of strain on material constants with a very good correlation and generalization (Fig. 5).…”

“…Figure 2b indicates the flow stress of ZA27 alloy decreases with the increase of deformation temperature at a constant strain rate. This is because lower strain rates and higher temperatures can provide higher mobility at boundaries for the nucleation and growth of dynamically recrystallized grains, and longer time for energy accumulation and dislocation annihilation [8,9].…”

“…Among these alloys, ZA27 exhibits attractive physical and mechanical properties combined with high tensile strength and wear resistance properties, making it a bearing alloy as replacement of their conventional counterparts like aluminum casting alloys, bearing bronzes, and cast iron in various engineering applications [2][3][4][5][6]. To meet the growing demands for application of these alloys in industry, further investigations on the correlations among the thermo-mechanical process parameters, the microstructure evolution of the materials, and the mechanical properties need to be considered [7][8][9][10][11][12][13][14].…”

Electropulsing Induced Texture Evolution in the Recrystallization of Fe-3 Pct Si Alloy Strip

“…A large number of dislocations piled up and blocked at the grain boundaries and at the structural defects, such as dislocations, vacancies, and precipitates, inside the grains, where a great deal of strain energy accumulated. [5][6][7] The energy storage at the grain boundaries and the structure-distorted sites inside the grains varied in accordance with the dislocation movement mechanism. At the grain boundaries, accumulation and annihilation of dislocations occurred at the same time.…”

“…[1,2] As a new developing process, electropulsing was found to be more powerful than the thermal energy in improving microstructure and the properties of the alloys, and in strengthening the metallurgical processes. [5][6][7][8][9] Electropulsing treatment (EPT) was applied to obtain well-recrystallized grains and to retard the formation of annealing twins in the cold-worked alloys. [5,[10][11][12] However, few studies about the effect of electropulsing on recrystallization of Fe-3 pct Si alloy strip have been reported.…”