STUDY ON TENSILE PROPERTIES AND MICROSTRUCTURES OF DIFFERENT SITES IN Al-Si ALLOY CASTING COMPONENT

The tensile properties and microstructures of ZL114A alloy component with a complex shape are investigated at room temperature and 200 degrees C, using the tensile tests, scanning electron microscopy and electron backscattering diffraction. Both thin wall and thick structure exhibit excellent properties, of which max ultimate tensile strength and elongation at break reach 314 MPa and 2.5% at room temperature, respectively. The ultimate tensile strengths of thin wall are 40 MPa and 25 MPa greater than those of thick structure at room temperature and 200 degrees C, respectively. Moreover, the eutectic Si phases of thin wall exhibit a predominantly spherical morphology while of the morphology of thick structure are rod-like, resulting in the different mechanical properties between thin wall and thick structure. The fracture morphologies of thin wall and thick structure are studied to explain the difference in performance between thin wall and thick structure.