Development of the Production Technology of Cast Aluminum Matrix Composite by Alumina Strengthening Phase Synthesis in an Aluminum Melt

摘要

Currently, critical components and assemblies made of traditional materials do not always meet the increased requirements of designers and service conditions. One solution to this problem is the development and application of dispersion-strengthened metal matrix composites. According to the informational-analytical review, a new fabrication technology of aluminum-based dispersion-strengthened composite material is presented. The peculiarities of this technology are described and sample macro- and microstructures, as well as mechanical characteristics of as-cast samples, are presented. The synthesis of strengthening particles immediately in the melt makes it possible to fabricate composites in one stage and provide thermodynamic stability, dense contact, and good adhesion between the matrix and strengthening phase. The particle sizes of the solid phase are in a range from 3 m to 2 mm. The structural-and-phase state of the produced material is studied using optical metallography and X-ray diffraction analysis (a DRON-2 diffractometer). The microstructure is studied using a Keyence VHX-1000 microscope. The sample hardness is determined using a TKS-1M device, microhardness is determined using PMT-3 and HMV Shimadzu devices, ultimate strength is determined using ZD 10/90 and UME-10TM universal tensile testers, and impact strength is determined using an MK-30a pendulum impact tester. It is found that the variation in size and content of the strengthening phase makes it possible to vary mechanical properties of cast metal in a wide range. The application of the proposed technology will substantially decrease temporal and economical costs. A decrease in the fabrication cost of the dispersion-strengthened composite material is expected according to the results of the evaluative calculation.