A study on damping behaviour of aluminite particulate reinforced ZA-27 alloy metal matrix composites

ZA-27 based metal matrix composites (MMCs) have been prepared with 1, 2. 3, and 4% of reinforcement by the compocasting method. Sample specimens of di mensions 70X10X2 mm were machined from prepared ingots. The damping behavio r and dynamic Young's modulus of base alloy and the particulate reinforced composites were studied over a temperature range of 30-300 degreesC using a dynamic mechanical analyzer. The damping capacity of the materials was obs erved to increase with the increase in temperature whereas the dynamic modu lus was found to decrease with the increase in temperature. The damping cap acity at lower temperature may be attributed to the coefficient of thermal expansion (CTE) mismatch induced dislocations and intrinsic damping of the matrix alloy, whereas damping capacity at higher temperature may be attribu ted to the matrix-reinforcement interface and thermoelastic damping. (C) 20 01 Elsevier Science B.V. All rights reserved.