The Effect of Adding Alumina Phases (alpha and amorphous) to Improve the Mechanical Properties (Compressive Strength and Hardness) of Polyester Matrix Composites. J. eng. sustain. dev. [Internet]. 2014 Nov. 1 [cited 2024 Jul. 3];18(6):202-11. Available from: https://jeasd.uomustansiriyah.edu.iq/index.php/jeasd/article/view/931