Preparation And Characterization Of WC-Al Matrix Composite Materials By In Situ Synthesis Method

Traditional preparation methods of particle-reinforced aluminum matrix composite materials are direct addition method, although we can get some composite materials those we need, but the properties are still difficult to meet the increasing demand of the work environments of equipment. In order to further improve the properties of particle-reinforced aluminum matrix composites, a new preparation methods of particle-reinforced aluminum matrix composites was adopted, and compared with direct addition method for researching advantage of the new method on improving properties.Preparing WC/Al alloy with in situ synthesis method, and verifying the feasibility of in situ synthesis of WC through the tests, such as SEM, EDS, XRD and XRF, and researching the basic parameters and results of in situ synthesis. The results show that: when the temperature reaches a certain requirement, WC particles could be prepared by in situ synthesis method; at 950 °C, efficiency of in situ synthesis reaction system was about 30%, WC content of WC/Al alloy is 9%. Adding K2 Ti F6 and K3 Al F6 into in situ system could effectively reduce the size of WC particles, the sizes of two groups WC particles were respectively 50 μm and 75 μm, the improvement of K2 Ti F6 was better.WC-Al matrix composite materials were prepared by stirring mixing casting method in this paper, and the reinforcing effect was investigated at the same time. The effect of WC content and particle size to properties of composite materials were studied in the same time. And through the mechanical property testing, macrostructure and microstructure examination, friction and wear analysis to assessed the experiment results. The results show that: when WC content was 7%, material obtained the optimal performance, tensile strength was 263 MPa, hardness was 71 HB, the average friction coefficient was 0.312, significantly lower than the substrate metals without adding WC particles.WC particles as enhancement in the preparation of aluminum matrix composites has requirements of granularity, preparing composite with alloys adding K2 Ti F6, K3 Al F6 and nothing, supplemented by direct addition method with WC particles in different granularity, researching the effect of granularity on friction and wear properties, then ≤74μm WC particles were used as the reinforcing phase, performance of the materials was better.Using WC/Al alloy to prepare WC-Al matrix composite materials, and contrasting the WC-Al matrix composite materials prepared by different methods through the mechanical property testing, macrostructure and microstructure examination, friction and wear analysis. Based on the results of contrast, advantages of in situ synthesis method were studied. The results show that: the composite materials prepared by in situ synthesis method can be more uniform and have thinner microstructure, and in situ synthesis method avoided the microstructure defect appeared in direct addition method; the composite materials prepared by in situ synthesis method obtained more excellent mechanical properties and friction and wear performance.