Influence Law of Process Parameters on the Continuity and Dimensional Uniformity of 7075 Aluminum Alloy Single Tracks Manufactured by Selective Laser Melting

Abstract

7075 aluminum alloy powders were used as raw materials. The selective laser melting single tracks forming experiment of 7075 aluminum alloy was carried out at scanning speed of 50–700 mm s−1, laser power of 80–100 W. The continuity and dimensional uniformity of selective laser melting 7075 aluminum alloy single tracks were characterized by OM and SEM. The influence law of laser power and scanning speed on the continuity and dimensional uniformity of selective laser melting 7075 aluminum alloy single tracks were revealed. The results show that: when the laser power was increased from 80 to 100 W and the scanning speed of 50–700 mm s−1, the continuity and dimensional uniformity of selective laser melting 7075 aluminum alloy single tracks were improved, the morphology was changed from discrete irregular particles to continuous single line. When the laser power was 80 W, the continuity of selective laser melting 7075 aluminum alloy 3D printing single tracks was deteriorated, but the dimensional uniformity was improved, with the increases of scanning speed from 100 to 700 mm s−1. When the laser power was 100 W, the continuity and dimensional uniformity of the 7075 aluminum alloy selective laser melting 3D printing single tracks were improved with the increases of scanning speed from 50 to 300 mm s−1; the continuity and dimensional uniformity of the 7075 aluminum alloy selective laser melting 3D printing single tracks reduced with the increase of scanning speed from 500 to 700 mm s−1. Laser power has a great impact on the continuity and dimensional uniformity of 7075 aluminum alloy selective laser melting 3D printing single tracks, high laser power and low scanning speed are beneficial to obtaining continuous and dimensional homogeneous of the 7075 aluminum alloy single tracks.