Mechanical, microstructural and tribological behavior of stir cast Al8011/TiB2/SiC hybrid metal matrix composites

Abstract

Modern technology requires enriched mechanical and thermal characteristics. In the present scenario, the decent mechanical and thermal properties of hybrid Metal matrix composites (MMCs) make them more demanding in various fields such as automotive, aviation, and structural applications. In this paper, an attempt has been made to fabricate the composite Al8011 + TiB2 + SiC with 9 different weight fractions follows as reinforcement 1(TiB2) by 2%,4%, and 6% with varying reinforcement 2(SiC) percentage by 1%,3%, and 5%. Fabrication is made through the stir casting technique by considering ideal process parameters such as stirring temperature, stirring speed, stirring time, preheating temperature, grain size, and wt.% of particulate reinforcements. With the help of Electron discharge machining (EDM), the specimens for the tests performed were cut according to the ASTM standards. The test results in the present investigation revealed that an increase in mechanical properties has been detected with the addition of reinforcements when compared with individual matrix and reinforcement materials. Wear test analysis illustrates that increase in resistance to wear of composite with the increase in TiB2 percentage of reinforcement. According to the microstructural analysis, an increase in stirring speed and stirring time reduces porosity. X-ray diffraction was used to identify crystalline phases of various MMCs. A unit cell dimensions can also be calculated based on the diffraction peak positions obtained from the X-ray diffractometer (XRD) test. The process of determining the unit cell dimensions from peak positions is known as indexing. Miller indices, hkl, must be assigned to each peak in a powder diffraction pattern to index it. The process of indexing electron diffraction patterns of a single crystal is to label the individual diffraction spots with their proper values and sign (+or -) of h, k, and l. When x-rays are scattered from a crystal lattice, peaks of scattered intensity are observed which correspond to the condition, the Angle of incidence = Angle of scattering and the path length integer is equal to an integer number of wavelengths. The condition for maximum intensity contained in Bragg's law above allows us to calculate details about the crystal structure, or if the crystal structure is known, to determine the wavelength of the x-rays incident upon the crystal. Indexing of diffraction patterns was done for all the metal matrix composites and in which the miller indices and interplanar d- spacing were calculated.