EFFECT OF CNT/TIB2 PARTICLE ON MECHANICAL, METALLURGICAL BEHAVIOUR OF MAGNESIUM (AZ91D) COMPOSITES

Carbon Nano tubes (CNT) and Titanium di Boride particles (TiB2) with different weight percentages reinforced composite magnesium alloy (AZ91D) were fabricated and the impact of changes in the mechanical and metallurgical properties of composites was assessed. Different weight percentage strengths of CNT (1.5 percent) and TiB2 particles (5 %, 10%, 15 %) were applied to AZ91D grade magnesium alloy for various stir casting system process parameters in this study. For reinforcement-matrix interfacial reactions, SiC and Al2O3 were also added. The composites with 10% TiB2 and (1.5 % CNT+1 % SiC+1% Al2O3) reinforcement show high hardness, whereas other reinforcements show increased elongation. The presence of elements revealed by energy dispersive X-ray spectroscopy also characterizes the composites using optical and scanning electron microscopy.

Microstructure, Mechanical, and Corrosion Behavior of Al2O3 Reinforced Mg2Zn Matrix Magnesium Composites

Powder metallurgy (PM) method is one of the most effective methods for the production of composite materials. However, there are obstacles that limit the production of magnesium matrix composites (MgMCs), which are in the category of biodegradable materials, by this method. During the weighing and mixing stages, risky situations can arise, such as the exposure of Mg powders to oxidation. Once this risk is eliminated, new MgMCs can be produced. In this study, a paraffin coating technique was applied to Mg powders and new MgMCs with superior mechanical and corrosion properties were produced using the hot pressing technique. The content of the composites consist of an Mg2Zn matrix alloy and Al2O3 particle reinforcements. After the debinding stage at 300 °C, the sintering process was carried out at 625 °C under 50 MPa pressure for 60 min. Before and after the immersion process in Hank’s solution, the surface morphology of the composite specimens was examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis. With the hot pressing technique, composite specimens with a very dense and homogeneous microstructure were obtained. While Al2O3 reinforcement improved the mechanical properties, it was effective in changing the corrosion properties up to a certain extent (2 wt.% Al2O3). The highest tensile strength value of approximately 191 MPa from the specimen with 8 wt.% Al2O3. The lowest weight loss and corrosion rate were obtained from the specimen containing 2 wt.% Al2O3 at approximately 9% and 2.5 mm/year, respectively. While the Mg(OH)2 structure in the microstructure formed a temporary film layer, the apatite structures containing Ca, P, and O exhibited a permanent behavior on the surface, and significantly improved the corrosion resistance.

Proses Pembuatan Komposit Matriks Logam Al5Cu4Mg/Al2O3(p) dengan Metode Pengadukan dan Tempa

AbstrakKomposit Matriks Logam (KML) merupakan salah satu material yang banyak digunakan di industri manufaktur terutama yang berbasis alumunium, karena logam ini mempunyai berat jenis yang rendah. Pada saat ini pembuatan KML bermatriks alumunium dengan penguat Al2O3 sudah banyak dibuat dan digunakan di industri. Proses pembuatan KML di Indonesia merupakan hal yang baru-baru ini ramai diminati, meskipun penelitian awal sudah dilakukan jauh sebelumnya. Faktor penting pada pembuatan KML adalah menghidari adanya keropos atau adanya porositas pada hasil produk. Oleh karena itu, pada percobaan ini setelah dilakukan proses pengadukan dilanjutkan dengan proses tempa untuk mengurangi adanya porositas tersebut. Bahan yang digunakan sebagai matriks adalah Al-5%Cu-4%Mg dimana Mg sebagai wetting agent, sedangkan penguat yang digunakan adalah 5 dan 10% Vf Al2O3. Pengujian mekanik yang dilakukan antara lain uji tarik, kekerasan dan keausan, sedangkan pengujian fisik, yaitu: metalografi, berat jenis, porositas, SEM/EDS dan XRD, untuk melihat fasa dan senyawa baru. Hasil pengujian menunjukkan dengan adanya penguat Al2O3 terjadi kenaikkan sifat mekanik antara lain dengan naiknya angka kekerasan dan naiknya nilai ketahanan aus. AbstractThe Metal Matrix Composite (MMCs) is one of the widely used materials in the manufacturing industry, especially those based on aluminum, because this metal has low specific gravity. At this time, aluminum matrix KML with Al2O3 reinforcement has been widely made and used in industry. The process of making MMCs in Indonesia have just developed recently, even tough the previous research have been conducted for a long time. The important factor in making MMCs in to prevent the porosity at it’s product. This is the reason why we conduct a forging process after the agitation process. The materials used as matrix is Al-5%Cu-4%Mg where Mg is the wetting agent, while the reinforcement used is 5 and 10% Vf Al2O3. Mechanical tests include: tensile, hardness and wear tests, while physical tests: metallography, specific gravity, porosity, SEM/EDS and XRD, to see new phases and compounds. With the addition of Al2O3 reinforcement there is an increase in mechanical properties, among others, by increasing the number of hardness and increasing wear resistance.

Development and Mechanical Characterisation of Al6061-Al2O3-Graphene Hybrid Metal Matrix Composites

MMC based on aluminium (Al) were produced for light-weight applications especially in aviation and automobile areas. Present paper deals with the fabrication and mechanical performance of AA6061 matrix composites fortified with Al2O3 (alumina) and graphene particulates. Fluid metallurgy method namely stir casting route was employed for fabricating the hybrid composites. Al2O3p and graphene powder are mixed in different weight fractions in which graphene (1 wt. %) particle reinforcement is held consistent and Al2O3 reinforcement is differed freely with 5, 10 and 15 wt. %. Using optical analyser and SEM equipment, microstructural examination is carried out and the result reveals that the graphene and Al2O3 particles prevalently are homogeneously appropriated on the grain limits of Al matrix and Al2O3 particles are disseminated between graphene in the as-cast AA6061 MMC’s. Detailed analysis on investigation of the microstructure and mechanical aspects of Al6061-graphene-Al2O3p composites is presented by following ASTM guidelines; results uncovered that with increment in reinforcement particles, there is an enhancement in the hardness, ultimate strength, yield strength and a decline in the elongation values was however noticed when contrasted with Al6061 alloy. Fractography investigation revealed dimples in unreinforced alloy and the composite.

Tool Wear Prediction Based on Artificial Neural Network during Aluminum Matrix Composite Milling

This article deals with the phenomenon of tool wear prediction in face milling of aluminum matrix composite materials (AMC), class as hard-to-cut materials. Artificial neural networks (ANN) are one of the tools used to predict tool wear or surface roughness in machining. Model development is applicable when regression models do not give satisfactory results. Because of their mechanical properties based on SiC or Al2O3 reinforcement, AMCs are applied in the automotive and aerospace industry. Due to these materials’ abrasive nature, a three-edged end mill with diamond coating was selected to carry out milling tests. In this work, multilayer perceptron (MLP) models were used to predict the tool flank wear VBB and tool corner wear VBC during milling of AMC with 10% SiC content. The signals of vibration acceleration and cutting forces were selected as input to the network, and the tests were carried out with three cutting speeds. Based on the analysis of the developed models, the models with the best efficiency were selected, and the quality of wear prediction was assessed. The main criterion for evaluating the quality of the developed models was the mean square error (MSE) in order to compare measured and predicted value of tool wear.