(南昌航空大學(xué)輕合金加工科學(xué)與技術(shù)國防重點(diǎn)學(xué)科實(shí)驗(yàn)室，南昌 330063)
摘 要: 采用陶瓷和尼龍復(fù)合纖維增強(qiáng)熔模精鑄硅溶膠型殼，通過測試與分析復(fù)合纖維增強(qiáng)硅溶膠型殼的常溫及焙燒后強(qiáng)度和透氣性，研究復(fù)合纖維含量對硅溶膠型殼強(qiáng)度和透氣性的影響規(guī)律，確定復(fù)合纖維含量與焙燒溫度和型殼強(qiáng)度的關(guān)系，并通過SEM對型殼試樣斷口形貌進(jìn)行觀察和分析。結(jié)果表明：復(fù)合纖維對硅溶膠型殼強(qiáng)度和透氣性的影響顯著，當(dāng)復(fù)合纖維含量小于0.6%(質(zhì)量分?jǐn)?shù))時，硅溶膠型殼強(qiáng)度和透氣性同時增大；當(dāng)復(fù)合纖維含量大于0.6%時，型殼常溫及焙燒后強(qiáng)度開始減小，焙燒后基體中孔隙率增加，型殼透氣性繼續(xù)增大；當(dāng)復(fù)合纖維含量為0.6%、焙燒溫度為1050 ℃時，型殼焙燒后強(qiáng)度達(dá)到最大值。
關(guān)鍵字: 熔模精鑄；硅溶膠型殼；復(fù)合纖維含量；強(qiáng)度；透氣性
（National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology,
Nanchang Aeronautical University, Nanchang 330063, China）
Abstract:Ceramic and nylon composite fibers were used to enhance silica sol shell of investment casting. The effects of composite fiber content on the strength and breathability of silica sol shell were studied by testing and analyzing the green and fired strength and breathability. Meanwhile, the relationships among composite fiber content and firing temperature and fired strength of shell were established. The fracture appearances of shell specimens were observed by scanning electron microscopy (SEM). The results indicate that the effect of composite fibers on strength and breathability of silica sol shell is obvious. When composite fiber content is less than 0.6% (mass fraction), the strength and permeability of silica sol shell both increase. When composite fiber content is more than 0.6%, the green strength and fired strength of fiber-reinforced shell decrease firstly, and the matrix porosity increases, the shell breathability continues to increase; When the composite fiber content is 0.6% and firing temperature is 1050 ℃, the fired strength reaches maximum value.
Key words: investment casting; silica sol shell; composite fiber content; strength; breathability
