Effect of the high energy milling on the microstructure of Cu-20%WC composite powders prepared with recycled WC

• Published in: International journal of refractory metals & hard materials 2020-08, Vol.90, p.105223, Article 105223
• Main Authors: Raimundo, Rafael A., Costa, Franciné A., Morales, Marco A., Silva, Angelus G.P., Gomes, Uílame U.
• Format: Article
• Language: English
• Subjects: Agglomerates; Cobalt; Compressive properties; Copper; High energy milling; Iron; Magnetic properties; Mechanical alloying; Metal scrap; Microstructure; Particle size; Particulate composites; Plates; Recycled WC; WC-Cu composite powder; WC-Cu pseudo alloy
• ISSN: 0263-4368; 2213-3917
• DOI: 10.1016/j.ijrmhm.2020.105223

A mixture of Cu-20wt%WC was milled in a high energy mill for up to 50 h. The WC powder was recycled from hard metal scrap. It presents agglomerates of faceted WC particles and residual Co and Fe. In the first hours of milling, the Cu particles are deformed into plates, the agglomerates of WC are broken apart, the primary WC particles are fragmented and embedded in the Cu phase. Composite particles are formed. As milling proceeds, different plates are welded together and folded. The particle size increases. However, the hardened Cu becomes fragile and begin to break, decreasing the particle size. Both, Cu and WC are under compressive strain. Residual Co and Fe present in the recycled powder are dissolved in Cu and behave like the soft Cu phase. [Display omitted] •High energy milling of Cu and WC powders produces composite particles;•In the composite particles, WC fragments are embedded in a Cu softer matrix;•While the WC original particles are fragmented by milling, Cu is severely deformed;•The WC hard fragments pierce the Cu phase;•The crystal lattices of both phases are deformed and crystallite size decreases;•The particle size of the particles decreases during milling due to work hardening.