(合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，合肥 230009)
摘 要: 以超細(xì)SiC粉(W7)為原料制備的SiC多孔骨架為先驅(qū)體，采用無壓滲透工藝制備出致密、增強(qiáng)體分布均勻的SiC/Al復(fù)合材料。SiC-Al間存在厚度為0.3~0.5 μm的界面層，該界面層能很好地被鋁液潤濕，并阻止鋁液與SiC的接觸與反應(yīng)。SiC坯體滲入鋁合金后無形狀和尺寸的變化，能夠?qū)崿F(xiàn)制品的近凈成形。加入SiC后，鋁合金的強(qiáng)度顯著提高，彈性模量提高近1倍。細(xì)顆粒的SiC能更好地抑制鋁基體的熱膨脹。材料的熱學(xué)性能可通過SiC的含量來調(diào)整，SiC體積分?jǐn)?shù)介于37%至54%之間時(shí)，室溫導(dǎo)熱系數(shù)介于136 W/(m∙K)至118 W/(m∙K)之間，室溫至100 ℃的平均線熱膨脹系數(shù)介于9.98×10−6 K−1至7.69×10−6 K−1之間。
關(guān)鍵字: SiC/Al；自發(fā)滲透；近凈成形；熱膨脹
（School of Materials Science and Engineering, Hefei University of Technology,Hefei 230009, China）
Abstract:Compact SiC/Al composites with SiC particles uniformly distributing were fabricated by spontaneous infiltration of liquid Z101 alloy into porous SiC preforms deriving from super-fine SiC powders (W7). An interface layer ranging from 0.3 μm to 0.5 μm in thickness exists between SiC filler and Al alloy matrix. The interfacial layer can be wetted well by liquid Al alloy and prevent the directly contact and reaction between liquid Al alloy and the filler. Preforms have no change in shape and dimension after infiltration thus the near-net-shape products can be achieved. The strength of aluminum alloy can be improved remarkably by the addition of SiC particles, and its elastic modulus increases correspondingly about one time. The finer SiC particulates restrict the thermal expansion of Al alloy matrix for more. The thermal properties of SiC/Al composites can be modulated by changing volume fraction of SiC: the thermal conductivity of SiC/Al composites at room temperature ranges from 136 W/(m∙K) to 118 W/(m∙K) and its mean linear coefficient of thermal expansion (room temperature to 100 ℃) ranges from 9.98×10−6 K−1 to 7.69×10−6 K−1 as volume fraction of SiC ranges from 37% to 54%.
Key words: SiC/Al; spontaneous infiltration; near-net-shape; thermal expansion
