Fabrication and characterization of unidirectional CF/Al composites

Abstract

The unidirectional carbon fi ber (CF) reinforced aluminum (Al) composites have been fabricated by the low pressure infi ltration (LPI) of molten Al into porous CF preform. Prior to the fabrication of the unidirectional CF/Al composites, the unidirectional CF preform was prepared by sintering of CFs and copper (Cu) particles under the spark plasma sintering (SPS). The compression strength of CF preform was examined to determine the infi ltration pressure of molten Al into CF preform. The effects of the different infi ltration pressures and sizes of Cu particles on the densifi cation of unidirectional CF/Al composites have also been investigated. The compression strength of CF preform increased with increasing of the contact area between CFs and Cu particles. The density of CF/Al compo sites improved with the increase of the infi ltration pressure. The CF/Al composites, into which the bimodal Cu particles are added, have average particle sizes of 2.55 µ m and 11.79 µ m, with a high relative density of about 95 % with the nearly homogeneous fi ber distribution.

Effect of alumina coating and extrusion deformation on microstructures and thermal properties of short carbon fibre–Al composites

“…On one hand, TC value of the alumina coating is relatively low (nearly 36 W m −1 K −1 [23]), which may have a bad effect on the improvement of TC of the composites. On the other hand, alumina coating can act as the diffusion barrier to reduce the formation of Al 4 C 3 , which is harmful to TC of the composites [12]. Therefore, the result of this study shows that the beneficial effect dominates the effect of alumina coating on TC values of the composites.…”

“…For SCF-Al composites, it is widely accepted that carbon fibres would react with aluminium to form brittle Al 4 C 3 , which is harmful to both mechanical and thermal properties of the composites [11][12][13][14]. An effective method to solve this problem is to coat the carbon fibres with protection coatings [11][12][13][14][15].…”

“…For SCF-Al composites, it is widely accepted that carbon fibres would react with aluminium to form brittle Al 4 C 3 , which is harmful to both mechanical and thermal properties of the composites [11][12][13][14]. An effective method to solve this problem is to coat the carbon fibres with protection coatings [11][12][13][14][15]. Among all the coatings being considered in carbon fibre-reinforced aluminium (CF-Al) composites, alumina coating has attracted much attention due to the fact that it can act as diffusion barrier to impede interfacial reactions [16][17][18][19].…”

Effect of thermal exposure on the microstructure of the interface in a Grf/Al composite

“…Hihara [12] found that the aluminum carbide hydrolyzed at a rate of ∼ 1%/h indicated that the degradation resistance of G/Al composites would be severely compromised by the presence of Al 4 C 3 . The reason is that Al 4 C 3 has an unstable chemical property, absorbing water in the surrounding medium and reacting to produce CH 4 and Al(OH) 3 . More over, the expansion of these products in the interface leads to the peeling of reinforcements from the matrix.…”

Effect of SiO2 amount on microstructures and tensile properties of alumina short fiber-reinforced composites by low-pressure infiltration method

“…Although the MMCs are very attractive materials for automobile industry, the raw materials and its manufacturing method are not cost effective compared with the conventional materials and its manufacturing system. However, the low-pressure infiltration method [5][6][7] is one of the useful casting methods for MMCs, due to apply low-pressure in comparison with high pressure casting such as die casting and squeeze casting. 8,9 Furthermore, low pressure is able to produce complex/ large shape and accomplish high cost-performance.…”