(1. 河南科技大學(xué) 材料科學(xué)與工程學(xué)院，洛陽(yáng) 471023；
2. 河南科技大學(xué) 河南省有色金屬材料科學(xué)與加工技術(shù)重點(diǎn)實(shí)驗(yàn)室，洛陽(yáng) 471023)
摘 要: 采用單輥快速凝固法制備出Mg80-xAlxCu15Y5(x=0，1)合金薄帶，再將薄帶在不同溫度下進(jìn)行退火處理，利用XRD、DSC和HRTEM分析Al元素對(duì)Mg80-xAlxCu15Y5(x=0，1)合金薄帶的非晶形成能力及熱穩(wěn)定性的影響。結(jié)果表明：Al的加入使得Mg-Cu-Y合金的玻璃轉(zhuǎn)變溫度和初始結(jié)晶溫度升高，過(guò)冷液相區(qū)寬度ΔTx因Al部分置換Mg而增大，約化玻璃轉(zhuǎn)變溫度Trg從0.616升至0.631，合金的非晶形成能力及熱穩(wěn)定性提高。隨著退火溫度的升高，Mg79Al1Cu15Y5合金的晶化率低于Mg80Cu15Y5合金的。當(dāng)退火溫度為523 K時(shí)Mg80-xAlxCu15Y5(x=0，1)合金均發(fā)生明顯晶化，在非晶基體上彌散析出大量HCP-Mg和Mg2Cu納米顆粒；當(dāng)溫度升高至573 K時(shí)，Mg79Al1Cu15Y5合金中有針狀A(yù)lMg化合物相形成。
關(guān)鍵字: 鎂基非晶合金；非晶形成能力；熱穩(wěn)定性；晶化
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Henan Key Laboratory of Advanced Non-ferrous Metals,
Henan University of Science and Technology, Luoyang 471023, China）
Abstract:Mg80-xAlxCu15Y5(x=0,1) alloy ribbons were prepared by single-roll rapidly solidification method. Then the samples were annealed at various temperatures. The effects of Al on the glass forming ability (GFA) and thermal stability of Mg80-xAlxCu15Y5(x=0,1) alloys were studied by XRD, DSC and HRTEM. The results show that Al addition enhances the glass transition temperature and the onset temperature of crystallization of Mg-Cu-Y alloy. The width of supercooled liquid region ΔTx is found to become larger with partial substitution of Mg by Al, and the reduced glass transition temperature Trg increases slightly from 0.616 to 0.631, which result in the improvement of the glass forming ability and thermal stability. With the increase of annealing temperature, the crystallization degree of Mg79Al1Cu15Y5 alloy is lower than that of Mg80Cu15Y5 alloy. The remarkable crystallization behavior of Mg80-xAlxCu15Y5(x=0,1) alloys occurs after being annealed at 523 K, while the dispersed precipitation of HCP-Mg and Mg2Cu nanoparticles takes place in the amorphous phase matrix. The acicular-shaped AlMg compound phase is formed in Mg79Al1Cu15Y5 alloy annealed up to 573 K.
Key words: Mg-based amorphous alloys; glass forming ability; thermal stability; crystallization
