(上海交通大學(xué) 國(guó)家輕合金精密成型工程中心， 上海 200030)
摘 要: 研究了不同稀土鈰含量對(duì)AZ61合金顯微組織和力學(xué)性能的影響。 實(shí)驗(yàn)發(fā)現(xiàn)： 加入稀土鈰后， AZ61合金鑄態(tài)組織的β相變少、 變細(xì)， 鑄態(tài)晶粒細(xì)化； 大部分鈰與鋁結(jié)合生成高熔點(diǎn)、 高熱穩(wěn)定性的稀土相Al4Ce； 在熱擠壓和退火過程中， Al4Ce能夠阻礙晶粒或亞晶粒的長(zhǎng)大, 使晶粒細(xì)化。 適量的稀土鈰提高了擠壓態(tài)合金的強(qiáng)度、 延伸率和顯微硬度； 而過量的稀土鈰則會(huì)導(dǎo)致AZ61合金的性能下降； 含1.0％稀土鈰的擠壓態(tài)合金可得到最高的抗拉強(qiáng)度308.1MPa、 最高屈服強(qiáng)度180.1MPa、 最大的顯微硬度HV80.5和最高的延伸率14.2％； 所有試驗(yàn)合金的斷裂方式是解理斷裂。
關(guān)鍵字: AZ61+Ce； 擠壓； 顯微組織； 力學(xué)性能
of AZ61 wrought magnesium
DING Wen-jiang, ZHU Yan-ping
（National Engineering Research Center of Light Alloys Net Forming,School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200030, China）
Abstract: Effects of Ce addition on the microstructures and mechanical properties of the AZ61 alloy have been investigated. It is found that Ce makes refinement of Mg17Al12 and grains, and decreases the amount of Mg17Al12 phase. Most of Ce reacts with aluminum to form compounds of Al4Ce with high melting point and elevated temperature stability which retards grain growth during hot deformation. Certain amount of Ce increases tensile strength, yield strength, elongation and hardness. With more addition, Ce would combine more Al in matrix and decrease strengthening effect because Al4Ce phase would become coarsening. The mechanical tests indicate that AZ61 has the best properties when the content of Ce is 1.0％. Maximum tensile strength, maximum yield strength and maximum elongation are 308.1MPa, 180.1MPa and 16.2％, respectively. The fracture mechanism of AZ61+Ce alloys is cleavage.
Key words: AZ61+Ce; extrusion; microstructures; mechanical properties
