Study on the compaction characteristics of CNTs/TC4 composites based on electromagnetic warm compaction

Highlights: • The CNTs/TC4 powders were compacted by electromagnetic technology. • The effect of temperature on compaction characteristics of powders was studied. • The micro hardness and compressive strength of CNTs/TC4 were analyzed. • The micro-morphology and failure behavior of compacts were investigated. -- Abstract: Carbon nanotubes reinforced TC4 composites (CNTs/TC4) had good performance and wide application prospects, but it was difficult to form. In this paper, electromagnetic warm compaction (EMWC) technology was proposed to produce the CNTs/TC4 composite specimens, and the effect of temperature on its compaction characteristics was studied. Specifically, the density, micro-morphology, hardness and compressive strength of the compacts were obtained. Results showed that the density and hardness of the compacts gradually increased and then stabilized as the temperature increased. The compactness of the compact surface gradually decreased above 300 °C due to the influence of oxidized powders, while the internal compactness increased. The R-square of the density enhancement equation obtained by Gaussian fitting was 0.9842, which was more reliable than the traditional linear equation. The compressive strength of CNTs/TC4 gradually increased, and the maximum was 1182.38 MPa at 400 °C. The addition of CNTs increased the compressive strength of TC4 by more than 20%. The compactness of internal particles had a major influence on the compressive strength. Since there were obvious surface defects at 400 °C, the optimal EMPC temperature was 300 °C.