力學(xué)性能與斷裂行為
( 1. 江蘇大學(xué) 材料科學(xué)與工程學(xué)院， 鎮(zhèn)江 212013；
2. 江蘇大學(xué) 機(jī)械工程學(xué)院， 鎮(zhèn)江 212013)
摘 要: 利用Al-Zr(CO3)2原位反應(yīng)體系，采用熔體反應(yīng)法制備了(Al3Zr+ Al2O3)p/Al復(fù)合材料。 XRD及SEM分析顯示： 原位反應(yīng)生成的顆粒為Al3Zr和Al2O3，顆粒細(xì)小并均勻分布在基體中。 拉伸實(shí)驗(yàn)表明： (Al3Zr+Al2O3)p/Al復(fù)合材料的抗拉強(qiáng)度和屈服強(qiáng)度隨顆粒含量的增大顯著提高，當(dāng)顆粒體積分?jǐn)?shù)為10%時(shí)， 復(fù)合材料的抗拉強(qiáng)度和屈服強(qiáng)度分別為148.3MPa和110.5MPa， 但延伸率先上升后下降。 原位拉伸研究表明：復(fù)合材料拉伸過程中裂紋的萌生及擴(kuò)展機(jī)制可從兩方面得到解釋： 滑移過程中的位錯(cuò)作用機(jī)制以及顆粒脫粘和破碎形成的“孔洞”成核與長大機(jī)制。
關(guān)鍵字: 原位熔體反應(yīng)法； 拉伸實(shí)驗(yàn)； 裂紋； 位錯(cuò)
CHENG Xiao-nong1, CAI Lan2
（ 1. School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China;
2. School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, China）
Abstract: A new in-situ reactive system of Al-Zr(CO3)2 is used to prepare(Al3Zr+Al2O3)p/Al composites by melt method reaction. The XRD and SEM analysis indicate that the particles formed are fine Al3Zr and Al2O3, which are well distributed in the aluminum matrix. The ultimate tensile strength and yield strength are improved by increasing the volume fraction of the particle. The tensile properties are σb=148.3MPa and σs=110.5MPa when the particle volume fraction is 10%. But the elongation goes up firstly but then decreases. Crack initiation and propagation were observed by in-situ tensile experiment. The crack initiation and propagation can be interpreted with dislocation action mechanism and voids necleation and growth mechanism.
Key words: in-situ melt reaction method； tensile test； crack； dislocation
