Hot Tearing Defects of As-Cast Mg-xZn-0.5Y-0.5Zr Alloys

被引：0

作者：

Li X. ^{[1
]}

Liu Z. ^{[1
]}

Wang Y. ^{[1
]}

Wei Z. ^{[1
]}

Wang F. ^{[1
]}

Wang Z. ^{[1
]}

机构：

[1] School of Materials Science and Engineering, Shenyang University of Technology, Shenyang

来源：

Xiyou Jinshu/Chinese Journal of Rare Metals | 2020年 / 44卷 / 07期

关键词：

Hot tearing; I-phase(Mg[!sub]3[!/sub]Zn[!sub]6[!/sub]Y); Mg-xZn-0.5Y alloy; W-phase(Mg[!sub]3[!/sub]Zn[!sub]3[!/sub]Y[!sub]2[!/sub]);

D O I：

10.13373/j.cnki.cjrm.XY19060012

中图分类号：

学科分类号：

摘要：

The effects of different ratios of Zn on hot tearing susceptibility of Mg-xZn-0.5Y-0.5Zr (x=1.5, 2.5, 3.5 and 4.5 (%, mass fraction)) alloys were investigated by self-made "T" mold. The hot tearing tendency was characterized by observing the macroscopic hot crack at the hot spot of the "T" mold and the volume of the crack measured by the paraffin penetrant method. In addition, scanning electron microscope (SEM) was used to analyze the microstructure of the alloy and the free fracture surface of the alloy. The phase analysis was carried out by X-ray diffraction (XRD) and transmission electron microscope (TEM) to determine the main composition of the low melting phase, and then the effect on the thermal cracking defects was studied. The A/D digital-to-analog converter was used to perform temperature-stress acquisition on the solidification. The results showed that the main phases of Mg-xZn-0.5Y-0.5Zr alloy were α-Mg, W-phase (Mg3Zn3Y2) and I-phase (Mg3Zn6Y). With the increase of Zn content from 1.5% to 4.5%, the precipitated phase content at low melting increased obviously, which improved the feeding ability of residual liquid between dendrites, effectively prevented crack initiation and propagation. When the Zn content was low, liquid membrane theory and solidification shrinkage compensation theory were the main theoretical basis for the interpretation of crack initiation. With the increase of Zn content and sufficient feeding of residual liquid, bridging theory was the main mechanisms of hot tearing formation. The order of hot tearing sensitivity of alloys was Mg-1.5Zn-0.5Y-0.5Zr, Mg-2.5Zn-0.5Y-0.5Zr, Mg-3.5Zn-0.5Y-0.5Zr, Mg-4.5Zn -0.5Y-0.5Zr. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.

引用

页码：697 / 705

页数：8

共 41 条

[1]

Tahreen N, Chen D L., A critical review of Mg-Zn-Y series alloys containing I, W, and LPSO phases, Adv. Eng. Mater, 18, 12, (2016)

[2]

Feng Y, Mao P L, Liu Z, Wang Z, Qin J M, Wang F., Hot tearing susceptibility of MgZn4.5YxZr0.5 alloys and mechanism, China Foundry, 13, (2016)

[3]

Wang F, Dong H K, Wang Z, Mao P L, Liu Z., Hot cracking behavior of Mg-5Al-xCa alloys, Acta. Metall. Sin, 53, 2, (2017)

[4]

Du B N, Hu Z Y, Sheng L Y, Xu D K, Zheng Y F, Xi T F., Influence of Zn content on microstructure and tensile properties of Mg Zn-Y-Nd alloy, Acta. Metall. Sin (Eng. Lett), 31, 4, (2018)

[5]

Zhao C, Chen X, Pan F., Strain hardening of as-extruded Mg-xZn (x=1%, 2%, 3% and 4%) alloys, J. Mater. Sci. Technol, 35, 1, (2019)

[6]

Zhou L., Investigations on Hot Tearing Sensitivity and Microscopic Mechanism of Mg-Zn-(Al) Alloys, 1, (2011)

[7]

Wang B, Liu Z, Mao P L, Wang Z, Wang F., Effect of Sn on thermal cracking sensitivity of Mg-Al-Ca alloys, Chinese Journal of Rare Metals, 40, 7, (2016)

[8]

Chen W, Liu C M, Su Z J., Microstructure and mechanical properties of as-cast Mg-2Nd-0.2Zn-0.4Zr-xY magnesium alloy, Journal of Central South University, 43, 6, (2012)

[9]

Wang H H, Liang H H., Effect of Y on microstructure and properties of Mg-Nd-Zn-Zr alloy, Journal of Central South University, 43, 1, (2012)

[10]

Davis T A, Bichler L, D'Elia F., Effect of TiB or on the grain refinement and hot tearing susceptibility of AZ91D magnesium alloy, J. Alloys. Compd, 759, (2018)

← 1 2 3 4 5 →