Hardness and Wear Properties of Al–4.5%Cu/Al₃Mg₂ Nanocomposite Prepared by Mechanical Alloying

Abstract

AlMg alloys close to ¢-Al 3 Mg 2 intermetallic phase were processed by neutral gas coverage melting process of pure elemental Al and Mg with the composition of Al40 mass% Mg. Mechanical milling was applied in order to convert the pre-alloyed ingots to nanocrystalline or amorphous alloy. X-ray diffraction and transmission electron microscopy (TEM) tests were carried out to investigate the formation of Al 3 Mg 2 single phase nanoparticle. Having prepared the single phase intermetallic, it was added to the pre-alloyed matrix powder of Al4.5 mass% Cu, in different contents. The effect of the reinforcing agent on the microhardness and wear behavior of the nanocopmosites were studied thoroughly with the aid of press-sinter methodology and quantitative data recorders via pin-on-disk wear test. The results of microhardness tests revealed that the hardness of nanocomposites is significantly improved with increasing reinforcement content with in the matrix. The coexisted wear mechanisms, mainly delamination and abrasive, of the consolidated nanocopmosites were investigated through scanning electron microscopy (SEM) and TEM observations.

Evaluating Microstructure and High-Temperature Shear Behavior of Hot Extruded Al-Al₁₃Fe₄ Nanocomposite

“…It contains 102 atoms in its monoclinic crystal structure unit, and owes its superior properties to the large number of atoms in its crystal unit. 20,27) The single-crystal growth of a large structure of Al 13 Fe 4 CMA is previously reported. 27) Plastic deformation and interfacial properties of Al-Al 13 Fe 4 have been discussed for an in-situ composite consisting of Al matrix and Al 13 Fe 4 particles.…”

“…20,27) The single-crystal growth of a large structure of Al 13 Fe 4 CMA is previously reported. 27) Plastic deformation and interfacial properties of Al-Al 13 Fe 4 have been discussed for an in-situ composite consisting of Al matrix and Al 13 Fe 4 particles. 13,14,28) Also, it has been shown that Al 13 Fe 4 exhibits a high hardness of 815 HV, a density of 3.8 g/cm 3 , and an estimated surface energy of 2.04 J/m 2 .…”

“…3,4) Utilizing mechanical alloying (M/A) technique, various fractions (0, 1, 3, 5, 7 and 10 mass%) of nano-sized Al 13 Fe 4 particles were added to pure atomized Al (150 µm in size and 99.98% purity) matrix powder, under conditions discussed in our previous work. 3,4) The aim was to determine the optimum level of reinforcement yielding the best mechanical properties. Thus, the powder mixture was hot pressed at a pressure of 650 MPa at 450°C for 30 min under the flow of Ar gas.…”

“…For instance, the usage of ¢-Al 3 Mg 2 CMA as a reinforcing agent in Al and Al alloy matrices, 4,11,12) and the room-temperature dry sliding wear behavior of Al matrices reinforced with either AlCuFeB or AlCuFeCr CMAs 25,26) have been the subject of a few studies. Nevertheless, for systems of AMCs with a gradient composition of CMAs, there is no previous study that addresses the elevated temperature mechanical behavior, including the elastic modulus, yield strength, ultimate strength and ductility characteristics.…”

“…6) Common second phase reinforcing agents of AMCs include carbides, oxides, 7) nitrides, carbon-based structures (CNT, GO, graphite) 79) and different intermetallic compounds. 4,1014) In particular, SiC and Al 2 O 3 are among the commonly used ceramic reinforcements.…”