(1. 上海交通大學(xué)材料科學(xué)與工程學(xué)院，上海 200240；
2. 上海交通大學(xué)金屬基復(fù)合材料國(guó)家重點(diǎn)實(shí)驗(yàn)室，上海 200240；
3. 上海市先進(jìn)高溫材料及其精密成形重點(diǎn)實(shí)驗(yàn)室，上海 200240)
摘 要: 采用透射電鏡、掃描電鏡、三維原子探針等手段研究Al-Zr-Y合金的時(shí)效析出行為及Y含量對(duì)合金性能的影響規(guī)律。結(jié)果表明：Al-Zr-Y合金時(shí)效初期首先析出Al3Y相，可能成為Al3Zr時(shí)效析出的異質(zhì)核心；長(zhǎng)時(shí)間時(shí)效后，Y有向析出相和基體界面處偏聚的傾向，最終形成無(wú)核殼結(jié)構(gòu)的Al3(Zr,Y)復(fù)合析出相；在三元Al-Zr-Y合金中，由于Zr的存在，Y在α(Al)中的平衡固溶度大幅度下降，600 ℃下的平衡固溶度從0.13%(質(zhì)量分?jǐn)?shù))降至0.03%。Y含量較高的Al-0.30Zr-0.08Y在凝固及冷卻過(guò)程中，過(guò)飽和的Y轉(zhuǎn)變?yōu)檠鼐Ы绶植嫉腁l3Y共晶和晶內(nèi)一次析出微米級(jí)Al3Y顆粒，使鋁基體中的有效Y含量較Al-0.30Zr-0.03Y中的降低4倍。Al-0.30Zr-0.03Y合金在時(shí)效過(guò)程中表現(xiàn)出更高的形核密度、更小的析出相尺寸和更優(yōu)的抗粗化能力，合金的抗再結(jié)晶溫度達(dá)到500 ℃，比Al-0.3Zr和Al-0.30Zr-0.08Y合金的抗再結(jié)晶溫度分別高出125和75 ℃。
關(guān)鍵字: Al3(Zr,Y)；析出機(jī)制；形核密度；抗粗化；抗再結(jié)晶
（1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China;
3. Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, Shanghai 200240, China）
Abstract:The aging process of Al-Zr-Y and the effect of Y on the properties of alloy were studied by transmission electron microscopy, scanning electron microscopy and three dimensional atom probe. The results show that,the Al3Y precipitates form as the heterogeneous core at early aging stage of Al-Zr-Y alloy, which accelerates the diffusion and precipitation of Zr, Y has the tendency to cluster in the precipitate and matrix interface after long-time aging. Finally, Al3(Zr,Y) composite precipitates without core-shell structure forms in the alloy. The solubility of Y inα(Al) decreases from 0.13% to 0.03% (mass fraction) after aging at 600 ℃ for 50 h because of Zr. During solidification of Al-0.3Zr-0.08Y, supersaturated Y produces eutectic Al3Y along the grain boundaries and micron level Al3Yin the grain, which makes the content of Y in the matrix is 4 times lower than that of Al-0.30Zr-0.03Y. Al-0.30Zr-0.03Y shows higher nucleation density, smaller precipitate radius and slower coarsening rate. The recrystallization temperature of Al-0.30Zr-0.03Y reaches 500 ℃, which is 125 and 75 ℃ higher than those of Al-0.3Zr and Al-0.3Zr-0.08Y, respectively.
Key words: Al3(Zr,Y); precipitation mechanism; nucleation density; coarsening resistance; recrystallization resistance
