Effect of Process Parameters on Microstructure and Micro-hardness of AZ91/Al2O3 Surface Composite Produced by FSP

Abstract

In this article, the effects of three different sizes of Al 2 O 3 particles in the friction stir processing on grain size, cluster size, microstructure, and micro-hardness of as-cast magnesium alloy AZ91 were investigated. Moreover, the effects of two types of tool geometries and number of passes on the mentioned parameters were considered. Effect of mentioned parameters on microstructure, grain refinement, and micro-hardness profile in the friction stirred zone of the specimens was compared by as-cast received form and also friction stir processed (FSPed) specimens without particles. Microstructural characterization of the materials revealed reasonably uniform distribution of Al 2 O 3 reinforcement and significant grain refinement. Hardness studies revealed that the incorporation of nano-and micro-size Al 2 O 3 particulates in magnesium matrix led to a simultaneous increase in hardness.

Different strategies of secondary phase incorporation into metallic sheets by friction stir processing in developing surface composites

“…Also, it reduces the necessity of using additional tool (without pin) to close the groove or holes before FSP. As reported by Faraji et al (2011) the distribution of secondary phase is uniform in sandwich method. But making the secondary phase into the form of layers or laminas is difficult particularly with hard and brittle ceramic materials.…”

“…Developing composites in solid state using FSP can address the issues associated with melting and solidification usually found in conventional processes. Aluminum, copper, titanium, magnesium, and their alloys are the mostly used metals as matrix materials and SiC (Mishra et al 2003;Alidokht et al 2013;Barmouz et al 2011;, WC (Khosravi et al 2014), MoS 2 (Alidokht et al 2013), Al 2 O 3 Raaft et al 2011;Yang et al 2010;Sharifitabar et al 2011;Azizieh et al 2011;Faraji et al 2011), CNTs (Liu et al 2013;Morisada et al 2007;Morisada et al 2006), B 4 C (Madhusudhan Reddy et al 2013;Sathiskumar et al 2013a), Ni particles (Devinder and Bauri 2011), carbon fibers (Mertens et al 2012), TiC , hydroxyapatite (Ratna Sunil et al 2014a;Ratna Sunil, et al 2014b;, and graphite (Soleymani et al 2012) are the widely used dispersing phases in producing surface composites using FSP.…”

“…Several studies have been carried out to estimate the potential of FSP to produce surfaces with enhanced surface hardness, wear resistance, and corrosion resistance and were clearly demonstrated in the literature (Faraji et al 2011;Liu et al 2013;Devinder and Bauri 2011;Ratna Sunil et al 2014a;Ratna Sunil et al 2014b;Soleymani et al 2012;Mishra et al 2014). The success of producing a composite using FSP depends on many factors such as tool design, processing parameters, and type of the material (Mishra et al 2014).…”

The effect of process parameters on microstructural characteristics of AZ91/SiO2 composite fabricated by FSP

“…The b-Mg 17 Al 12 is a coarse eutectic phase in the AZ91 microstructure. According to the Mg-Al phase diagram, dissolution temperature of eutectic b-Mg 17 Al 12 phase is about 437 1C in the magnesium matrix [15]. For the Al-Mg alloys, due to the low diffusion of aluminum in the magnesium matrix, dissolution of eutectic b-Mg 17 Al 12 phase is a very time consuming process [18].…”

Deformation behavior in the tubular channel angular pressing (TCAP) as a noble SPD method for cylindrical tubes

“…The most commonly used methods are equal channel angular pressing (ECAP) [2], high-pressure torsion (HPT) [3], and accumulative roll bonding (ARB) [4]. Yet there are other methods with different applications [5][6][7][8][9][10][11][12][13][14]. Of these various processes, ECAP is an especially attractive processing technique for several reasons.…”