(中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 以Mo、Si和聚碳硅烷為原料，采用先驅(qū)體轉(zhuǎn)化−反應(yīng)熱壓制備SiC/MoSi2納米復(fù)合材料，并研究納米SiC體積分?jǐn)?shù)對材料顯微結(jié)構(gòu)和力學(xué)性能的影響。結(jié)果表明，所制備的納米復(fù)合材料中含有MoSi2、SiC和極少量的Mo5Si3及SiO2。納米SiC的引入顯著地改善了材料的力學(xué)性能，15%SiC/MoSi2納米復(fù)合材料的綜合力學(xué)性能最好，其室溫抗彎強(qiáng)度和斷裂韌性分別為610 MPa和4.90 MPa/m1/2，比純MoSi2試樣的分別增加了141.1%和58.0%；其高溫抗彎強(qiáng)度在1 200和1 300 ℃時分別為720和516 MPa。
關(guān)鍵字: SiC/MoSi2納米復(fù)合材料；先驅(qū)體轉(zhuǎn)化；反應(yīng)熱壓；力學(xué)性能
（State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Using polycarbosilane, Mo and Si powders as raw materials, SiC/MoSi2 nanocomposites were fabricated by precursor conversion and reactive hot pressing. The effects of volume fraction of SiC nanoparticles on the mechanical properties and microstructure of SiC/MoSi2 nanocomposites were studied. The results show that the nanocomposites obtained consist of MoSi2, SiC, less Mo5Si3 and SiO2. The mechanical properties of the nanocomposites are dramatically improved by incorporating of SiC nanoparticles. 15%SiC/MoSi2 nanocomposite has the best comprehensive mechanical properties, with the flexural strength and fracture toughness of 610 MPa and 4.90 MPa/m1/2 at room temperature, which are increased by 141.1% and 58.0% compared with those of MoSi2, respectively. Its flexural strengths at 1 200 and 1 300 ℃ are 720 and 516 MPa, respectively.
Key words: SiC/MoSi2 nanocomposite; precursor conversion; reactive hot pressing; mechanical properties
