(華南理工大學(xué) 機(jī)械與汽車工程學(xué)院，廣州 510640)
摘 要: 采用機(jī)械合金化(MA)與放電等離子燒結(jié)(SPS)相結(jié)合的方法制備出FeCoNiCu0.4Al0.4高熵合金，研究不同熱處理溫度對(duì)合金顯微組織與力學(xué)性能的影響規(guī)律。結(jié)果表明：機(jī)械合金化后，F(xiàn)eCoNiCu0.4Al0.4高熵合金形成了單相的FCC固溶體，經(jīng)1100 ℃ SPS燒結(jié)后的塊體組織仍為單相FCC結(jié)構(gòu)，其壓縮屈服強(qiáng)度、塑性應(yīng)變和顯微硬度分別為1165.1 MPa、45.2 %和356.9 HV。經(jīng)過熱處理后，合金組織中生成了新的BCC相，且BCC相的含量隨熱處理溫度的升高先增多后減少，500、600和700 ℃熱處理后BCC相的含量分別為7%、30%和21%(體積分?jǐn)?shù))。退火態(tài)FeCoNiCu0.4Al0.4高熵合金的屈服強(qiáng)度隨熱處理溫度的升高先升高后降低。當(dāng)BCC相含量增多時(shí)，材料的屈服強(qiáng)度和硬度相應(yīng)地提高，而塑性卻顯著降低。
關(guān)鍵字: 高熵合金；機(jī)械合金化；放電等離子燒結(jié)；熱處理；相變
（School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China）
Abstract:The mechanically alloyed (MA) FeCoNiCu0.4Al0.4 high-entropy alloy (HEA) powders were sintered by spark plasma sintering (SPS) at temperature of 1100 ℃ and subsequently heat-treated at different temperatures. The microstructural evolution and mechanical properties of heat-treated HEAs were investigated. The results show that only a supersaturated face-centered cubic (FCC) structured solid solution forms during MA process. After sintering, the bulk FeCoNiCu0.4Al0.4 HEA also has a single FCC structure. The compressive yield strength, plastic strain and micro-hardness of sintered HEA are 1165.1 MPa, 45.2 % and 356.9 HV, respectively. BCC phase is precipitated from the FCC matrix during heat treatment process. The volume fractions of BCC phase in samples heat-treated at 500, 600 and 700 are 7%, 30% and 21%, respectively. The yield strength first increases and then decreases with the increase of heat treatment temperature. When the BCC phase fraction increases, the yield strength and hardness of HEA increase while the plasticity decreases obviously.
Key words: high-entropy alloy; mechanically alloying; spark plasma sintering; heat treatment; phase transition
