(西北工業(yè)大學(xué) 凝固技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，西安 710072)
摘 要: 以體積比為7:3的比例混合粒徑分別為75和15 μm兩種尺寸的SiC顆粒，將其分別在1 200 ℃高溫?zé)Y(jié)2、4、6、8和10 h后采用氣壓浸滲法制備SiC體積分?jǐn)?shù)為70%的SiCp/ZL101基復(fù)合材料，研究預(yù)制件高溫?zé)Y(jié)后復(fù)合材料的界面，討論氧化以及界面反應(yīng)對復(fù)合材料抗彎強(qiáng)度和導(dǎo)熱性能的影響，并利用實(shí)驗(yàn)熱導(dǎo)率反算實(shí)際界面?zhèn)鳠嵯禂?shù)。結(jié)果表明：雙尺寸的SiC顆粒在Al合金基體中分布均勻；SiC預(yù)制件的氧化改變了SiC顆粒與Al合金基體之間的結(jié)合形式，從而有效提高了界面結(jié)合強(qiáng)度，在1 200 ℃氧化4 h，其抗彎強(qiáng)度和熱導(dǎo)率均達(dá)到最高，分別為422 MPa和195 W/(m?K)。實(shí)際界面?zhèn)鳠嵯禂?shù)與復(fù)合材料熱導(dǎo)率變化一致。此外，氧化鈍化了SiC顆粒，其形貌的變化使得顆粒周圍基體中的應(yīng)力集中現(xiàn)象大大減少，提高了復(fù)合材料的抗彎強(qiáng)度，但是氧化時(shí)間過長的界面卻不利于載荷的傳遞和基體的形變約束。
關(guān)鍵字: SiCp/ZL101基復(fù)合材料；氧化；界面；抗彎強(qiáng)度；導(dǎo)熱性能
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The 75 and 15 μm SiC particles were mixed at a 7:3 volume ratio for SiC preforms, which were then oxidized at 1 200 ℃ for 2、4、6、8 and 10 h, respectively. The pressure in?ltration was carried out to fabricate SiCp/ZL101 matrix composites with SiC volume fraction of 70%. The interfaces with different holding times were investigated, and the effects of oxidation and interfacial reaction on flexural strength and thermal conductivity were discussed. The actual interfacial thermal conductance was back-calculated by experimental thermal conductivity. The results show that the distribution of dual-sized particles in Al alloy matrix is uniform. The bonding form changed by oxidation is considered to improve the bonding strength between SiC and Al. When being oxidized at 1 200 ℃ for 4 h, the flexural strength and thermal conductivity reach the maximum, which are 422 MPa and 195 W/(m?K), respectively. The interfacial thermal conductance back-calculated shows the same variation trend with the thermal conductivity of SiCp/ZL101 matrix composites. Besides, oxidation decreases the stress concentration in Al matrix around SiC particles, which improves the flexural strength of SiCp/ZL101 matrix composites. But if the oxidizing time is too long, the interface is detrimental to the transfer of loads and control of matrix deformation.
Key words: SiCp/ZL101 matrix composites; oxidation; interface; flexural strength; thermal conductivity
