Optimization of stir casting method of aluminum matrix composite (AMC) for the hardness properties by using Taguchi method

Aluminum matrix composite (AMC) was fabricated using stir casting with fly ash and SiC as reinforcing materials. In this work, Taguchi optimization technique was utilized to analyze the significant contributions of stir casting parameters on the hardness properties of AMC. For this reason, stir casting was carried out by utilizing the combination of process parameters based on three-level of L9 Taguchi. The signal-to-noise (S/N) and the analysis of variance (ANOVA) were used to find the optimum levels and to indicate the impact of the process parameters on the hardness properties. The results show that some of process parameters have significant effect on the hardness, by comparing with the other three sintering factors, the composition of reinforcement materials gave the most significant effect on the hardness

Rancang Bangun Alat Stir Casting Menggunakan Metode Pahl and Beitz Untuk Proses Pembuatan Komposit Matriks Aluminium

Porositas yang terjadi pada komposit matriks aluminium merupakan suatu masalah terbesar dalam proses pembuatan komposit karena material keramik yang memiliki perbedaan densitas, titik lebur dan titik didih. Akan tetapi material logam lain seperti aluminium, tembaga, magnesium dan lainnya memiliki densitas, titik didih dan titik lebur yang rendah. Oleh karena itu pencampuran partikel keramik SiC sulit terjadi dengan material logam matriksnya. Penelitian ini merancang bangun alat stir casting yang terdiri dari base stand, electrical box (temperatur controller), pin, penampang, pegangan hydraulic (handle), poros penahan, motor, pulley motor, pengencang, pulley (stirrer), pengaduk, belt, bantalan, baut, furnace, inverter, dan cetakan. Stir casting dibuat menggunakan metode Pahl and Beitz yang terdiri penetapan kebutuhan, perancangan konsep, perancangan detail, dokumen pembuatan produk dan produksi awal. Setelah menyelesaikan pembuatan alat stir casting, penelitian ini fokus pada pengeoperasian alat untuk membuat komposit dan menghitung nilai porositas dari komposit tersebu

Study of Properties of Al LM-25/SIC fabricated by using Stir Casting Method and Wear Analysis by RSM

Aluminum MMC’s are widely used in various applications because of their higher mechanical and physical properties when compared with their base Al alloy. This paper focuses on the change in mechanical properties of various Al/SiC composites fabricated by using stir casting method. Effect of SiC reinforcement in different Al alloys on mechanical properties like hardness, tensile strength, wear test, percentage elongation, residual stress measurements are discussed in detail. For this purpose various reinforcement of SiC with 0,4,8 percent weight and different particle sizes are considered along with Al alloys. Variations in process parameters of stir casting are also made and taken into consideration

Simulation of the stir casting process

Non homogeneous particle distribution is one of the greatest problems in casting Metal Matrix Composites (MMC's). To optimize some of the parameters for uniform particle distribution for batch compocasting the present simulation studies were conducted. The simulation involves visualisation experiments. In the visualisation experiments liquid and semi solid aluminium are replaced by other fluids with similar characteristics. SiC reinforcement particulate similar to that used in aluminium MMC's was used in the simulation fluid mixtures. Scaled-up stirring experiments were carried out in a transparent crucible with the percentage of reinforcement material being varied. Optimum conditions for photographing flow patterns were established. The dependence of the photography conditions (shutter speed, aperture control, lighting), particles dispersion and settling times and vortex height on stirrer geometry and speed was found. Results are discussed in terms of their applicability to MMC production

The Production Of Cast Metal Matrix Composite By A Modified Stir Casting Method

In a normal practice of stir casting technique, cast metal matrix composites (MMC) is produced by melting the matrix material in a vessel, then the molten metal is stirred thoroughly to form a vortex and the reinforcement particles are introduced through the side of the vortex formed. From some point of view this approach has disadvantages, mainly arising from the particle addition and the stirring methods. During particle addition there is undoubtedly local solidification of the melt induced by the particles, and this increase the viscosity of the slurry. A top addition method also will introduced air into the slurry which appears as air pockets between the particles. The rate of particle addition also needs to be slowed down especially when the volume fraction of the particles to be used increases. This is time consuming for a bigger product. This study propose a new approach of producing cast MMC. When all substances are placed in a graphite crucible and heated in an inert atmosphere until the matrix alloy is melted and then followed by a two-step stirring action before pouring into a mould has advantages in terms of promoting wettability between the silicon carbide particle and the A359 matrix alloy. The success of the incorporation of silicon carbide particles into the matrix alloy showed that the wettability between silicon carbide particles and mechanical properties such as hardness and tensile strength are comparable with previous data produced by other researchers

Modification of as-cast Al-Mg/B4C composite by addition of Zr

Zirconium was used in Al-Mg/B4C composite to improve compocasting efficiency by increasing particle incorporation. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) results revealed that by addition of zirconium a reaction layer containing Zr, Al, B and C is formed on the interface of B4C-matrix. X-ray diffraction (XRD) analysis of extracted particles unveiled that the ZrB2 phase is the main constituent of this layer. Formation of ZrB2 is an exothermic reaction which can rise temperature locally around particles and agglomerates. Rising temperature around agglomerates in conjunction with turbulent flow of melt facilitates agglomerates wetting and dissolving into molten aluminum. As the result, final product contains more uniformly distributed B4C particles. Besides enhancing compocasting efficiency, addition of Zr and formation of reaction layer by improving particle matrix bonding quality, led to increase in ultimate tensile strength and elongation of the composite around 8% and 30%, respectively. SEM observations of the fracture surfaces confirmed that a proper bonding presents at the interface of particles and matrix in presence of Zr.Peer ReviewedPostprint (author's final draft