Laser metal deposition for additive manufacturing of AA5024 and nanoparticulate TiC modified AA5024 alloy composites prepared with balling milling process

Abstract

Aluminum-magnesium (Al-Mg) alloys containing scandium (Sc) are high-performance lightweight materials. There is still limited research about the additive manufacturing of the materials with the powder-feeding-based laser metal deposition (LMD). This study aims to develop the processing of AA5024 (an Al-Mg alloy containing Sc) with LMD. On this basis, TiC nano-particles are added to the AA5024 powder, in order to seek an approach to reduce the need for Sc for enhancing or adjust the performance of AA5024. Both the pure AA5024 powder and the modified powder are used to build solid parts. Powder analyses are performed to identify the proper powder prepraration window of the ball milling. Mechanical tests, porosity analysis and microstructural analysis are conducted to evaluate the performance of the solid parts. Within the scope of this work, an average tensile strength of 347 MPa and an average yield strength of 296 MPa have been reached in specimens made of AA5024, after the specimens have been aged at 300 °C for 5 h. TiC additives are not able to strengthen and harden AA5024, but the TiC additions have shown a potent effect on homogenizing the microstructure.