Investigating of the Microstructure and Mechanical Properties of Al-Based Composite Reinforced with Nano-Trioxide Tungsten via Accumulative Roll Bonding Process

Abstract

In the present investigation, an Al/WO 3 p metal matrix nanocomposite was fabricated by accumulative roll bonding (ARB) technique. Microstructural evaluation and mechanical properties of specimens were studied by Field Emission-Scanning Electron Microscopy, X-ray Diffraction, microhardness and tensile test. Several factors that affect uniform distribution of reinforcing particles were investigated. At the initial stages of ARB process particle free zones as well as particle clusters were observed in the microstructure of the composite. After 12 ARB cycles, a nanocomposite with a uniform distribution of nanoparticles was produced. It was shown that the tensile strength of the ARBed composite enhanced with the increasing number of ARB cycles. After the first cycle, a significant increase was observed in the tensile strength of nanocomposite in 2.0 percent volume of WO 3p , from 89 MPa to 128 MPa (almost 1.4 times increase in strength). After the final cycle, the tensile strength value increased to 205 MPa (that is almost 2.3 times increase in strength) due to the strain hardening and grain refinement. The X-ray diffraction results showed that Al/WO 3p nanocomposite with the average crystallite size of 41 nm was successfully attained after 12 cycles of the ARB process. Finally, observations revealed that the fracture mode in Al/WO 3p nanocomposite was of type shearing ductile fracture with elongated shallow dimples.

Study of mechanical properties and wear resistance of nanostructured Al 1100/TiO2 nanocomposite processed by accumulative roll bonding

“…48 Finally, annealing and subsequent rolling caused the contact to become strongly bonded, making it difficult to locate the interface even with SEM examination. 49 ARB processing disseminated TiO 2 nanoparticles in the Al matrix very uniformly, as seen in Figure 4(d).…”

“…48 Finally, annealing and subsequent rolling caused the contact to become strongly bonded, making it difficult to locate the interface even with SEM examination. 49 ARB processing disseminated TiO 2 nanoparticles in the Al matrix very uniformly, as seen in Figure 4(d).

Figure 4.Scanning electron microscopy micrograph of Al - TiO 2 nanocomposite sheets after 5 accumulative roll bonding passes: (a) 1%, (b) 2%, (c) 3%, (d)larger magnification for sample with 3% TiO 2 .

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Advanced Metal Matrix Nanocomposites

“…Higher strength in the multi-pass ARBed samples is attributed to the grain refinement, strain hardening, and uniform distribution of the particles within the matrix ( Figure 13). Al-based (AA1100) composite reinforced with nano-tungsten trioxide (WO 3 ), with an average size of 80 nm and 1.0, 1.5, and 2.0 vol%, has been fabricated [81] for study of their microstructure and mechanical properties; good dispersion of nanoparticles within the matrix along with enhanced mechanical properties [81] was achieved upon 12 ARB cycles. Higher strength in the multi-pass ARBed samples is attributed to the grain refinement, strain hardening, and uniform distribution of the particles within the matrix ( Figure 13).…”

“…3D representation of tensile strength (a) and elongation (b) versus the volume fraction and the number of cycles[81].…”

Microstructure and Quasi-Static Mechanical Behavior of Cryoforged AA2519 Alloy

“…This results in a reduction of the grain size via the SPD process [4]. Several SPD methods such as Equal Channel Angular Pressing (ECAP) [5], Accumulative Roll-Bonding (ARB) [6], High Pressure Torsion (HPT) [7] and Multi Axial Forging (MAF) [8] have been developed. MAF is a relatively simple SPD process that consists of repeated compression in three orthogonal directions associated with a change in the axis to 90˚ in every pass leading to the attainment of a uniform texture with low aspect ratio grains within the material.…”