Papers by Keyword: Spontaneous Infiltration

Abstract: A porous SiC ceramic reinforced copper-matrix composite was fabricated by spontaneous infiltration of molten Cu-24at%Si alloy into the reinforcement. The influence of process parameters on the infiltration behavior and microstructure of the as-prepared SiC/Cu composite investigations showed that infiltration temperature had an important influence on the infiltration behavior, and higher infiltration temperature which decreased the viscosity of molten Cu-24Si was beneficial to the penetration. Besides, the degree of infiltration increased with the increase of dwelling time at 1600°C. SiC particles were bonded together by sintering additives to form the porous reinforcement, which can be maintained after spontaneous infiltration. The interfacial bond between SiC and Cu-24Si alloy was tight, and no obvious interfacial reaction layer was observed in the as-prepared composite.

Abstract: A three dimensional (3D) SiC/Cu-Si composite with bicontinuous structure was fabricated by spontaneous infiltration method, using porous recrystallized SiC ceramic with porosity of 37% as 3D network reinforcement and Cu alloy (Cu-18Si) as matrix. The phase composition, microstructure, and thermo-physical properties of the as-prepared 3D-SiC/Cu-Si composite were investigated. The experimental results showed that the Cu-18Si alloy could fully penetrate into the porous SiC ceramic at 1600 °C for 2 h spontaneously. SiC and Cu₁₅Si₄ phases were identified in the as-prepared composites. The interfacial bond between SiC and Cu-Si alloy was tightly and no severe interfacial reaction was observed. The thermal conductivity and coefficient of thermal expansion of the as-prepared 3D-SiC/Cu-Si composite were changed from 89.8 to 55 W·m^-1·K^-1 and 7.512 to 9.64×10^-6 °C^-1 with the temperature increased from room temperature to 500 °C, respectively.

Abstract: Reactive infiltration is a manufacturing process of metal matrix composites with low cost and low environmental impacts. In this study, reactive infiltration of a NiO/Ti blended powder preform with molten Al was examined. Titanium powder as an infiltration aid was mixed with NiO powder by various blending ratios. The preform and the Al ingot were then heated together up to 1273K ~1673K and held at these processing temperatures for 60 minutes by an induction furnace in N2 gas atmosphere. After the heating process, the vertical cross section was observed to see whether the infiltration and the in situ reaction occurred successfully. Spontaneous infiltration of molten aluminum into the powder preform did not occur when either processing temperature or blending ratio of titanium was not sufficiently high enough. Spontaneous infiltration occurred when processing temperature and volume fraction of titanium were 1273K, 1373K and 15%, 20%. But when volume fraction of titanium was 25%, the preform exploded by an extremely high. It was confirmed that Al3Ti, Al3Ni2 and Al2O3 were formed after the infiltration.