Review: additive manufacturing of pure tungsten and tungsten-based alloys

Tungsten is a refractory metal that has a wide range of applications in many fields. However, its high ductile-to-brittle transition temperature limits its processing and machining. While additive manufacturing is an emerging tool for manufacturing complex tungsten parts, cracking and low densification are the main challenges with printing W samples. Studies have been done using different additive manufacturing processes to fabricate high dense free of crack samples, without much success. To address this important challenge, extensive efforts have been made to investigate the effect of different processing conditions-such as laser/electron beam power, scanning speed, hatch spacing, and substrate preheating temperature-on the quality of the print. In this contribution, the most recent and relevant literature on the additive manufacturing of W and W-based alloys is reviewed. The literature is critically assessed in order to systematically investigate and report on the effect of different processing parameters on the morphology, densification, and mechanical properties of the additively manufactured W and W-based alloy parts.