Effect of tooltip profile and tilt angle on Al8090-TiH2/Al2O3 foam and its mechanical characterization

Abstract

Metal foams are used for industrial purposes because of their lightweight structure, high specific modulus of elasticity, and excellent energy-absorbing capacity. Various techniques have been used for the development of metal foam. In the present study, Al8090 foam is fabricated by the uniform mixing of TiH2/Al2O3 particles with the help of the stirring action of the tool probe. The groove cutting method is used to prepare the Al metal matrix and friction stir processing is performed over the grooves for even dispersion of the blowing powder to produce the precursor of the localized aluminium (Al) foam. Special purpose inclined fixtures with different angles are fabricated to produce tilt on the three-axis vertical machining centre. Three different tip profiles, namely plane cylindrical, threaded cylindrical and square are selected for processing along with the fixture plate angle set at three levels of 1°, 1.5° and 2.5°. Tool rotational and traversing speed rate is kept constant and its influence has been assessed on the foam's porosity, hardness and compressive strength. Scanning electron microscopy and energy-dispersive X-ray spectroscopy tests have also been performed to analyse the foam's morphology and found that the square tip pin with 1.5° fixture plate angle has the best mechanical properties.