Physical and Quantitative Microstructural Analysis of Sintered Al-Cu/SiCp Composites

Abstract

Al-Cu matrix composite materials with 5-20 wt. proportions of SiC hard particles and un-reinforced Al-Cu alloys obtained by powder metallurgy (P/M), in the same homogenization (20 r.p.m., about 7 hours)– pressing (450 MPa for composites) - presintering (300-420oC/30 min/H2) conditions but at different sintering temperatures (520-620oC/60min/H2, furnace cooling) were analyzed in terms of microstructural and physical characteristics. The existence of good bonding between metallic matrix and ceramic particles at interface and the morphology and distribution of pores and carbides in the matrix was evaluated by means of quantitative analysis. Using computer-assisted Optic Quantitative Microscopy on the samples, we determined the pore surface area for the studied materials and the surface area and grain size distribution of the SiC particles of sintered composites by analyzing the captured images in many fields. The hardness were correlated with quantity pore surface area and resulted that the lowest values of porosity were achieved at 620oC and at 10 and 15% silicon carbide in matrix.

Analytical and Experimental Studies on Wear Behaviour of Cast and Heat Treated Alsi12cumgni and Alzn6mgcu Matrix Composites Reinforced With Ceramic Particles, Under Sliding Condition

“…Discontinuous particle reinforced Metal Matrix Composites (MMCs) are particularly attractive because in addition to their low cost of manufacture, they can be shaped by conventional metalworking processes [6][7][8][9][10][11][12][13]33]. This has led to increased interest in the potential for large-scale use of particle reinforced MMCs in the automotive industry as materials for pistons, connecting rods, brake rotors, calipers and liners [34][35][36].…”

“…The wear behavior of Al2O3 particle reinforced MMCs has been extensively studied by various workers [5][6][7][8] and the tribological characteristics of Al-Si/Graphite for cylinder liners was studied in detail by B.P. Krishnan et.…”

“…[34]. The wear resistance of particulate reinforced MMCs depends mainly on the particle size, particle volume fraction and matrix alloy properties [1][2][3][4][5][6][7][8][9][10][11][12][13]. Al-Si alloys are commonly used in the manufacture of automotive engine components such as cylinder blocks, pistons and piston insert rings.…”

“…matrix) reinforced with soft ceramic particles (Graphite, MoS2 etc.) have the objective to: (i) stabilize the developed friction coefficient during braking, particularly at high temperatures; (ii) decrease wear of disc and also (iii) increase grippe resistance [1][2][3][4]; (iv) exhibit a low friction coefficient (compared to composites reinforced with hard ceramic particles [5][6][7][8]) are mostly used in tribological applications without lubrication. We could say that this type of material is a balance of mechanical resistance with reduced friction and wear.…”

Effects of Silicon Carbide Proportion and Artificial Aging Parameters on Microstructure and Hardness of Al-Cu/SiCp Composites

“…These changes depend on (a) the type of alloy used as matrix [1][2][3] ; (b) the processing route for obtaining the matrix alloy (if the matrix is obtained by the derived casting processing route or by processing in solid state including powder metallurgy techniques) [1,2], (c) the reinforcing characteristics (type, orientation, shape factor, proportion and size) [4] and (d) the physico-chemical compatibility between reinforcement and matrix [1][2][3]. Hard-reinforcing particles complicate the compaction behavior of powder mixtures [4][5][6] and influence the aging kinetics of materials [1][2][3][4][5][6][7][8][9][10][11].…”