Strengthening behavior of in situ-synthesized (TiC–TiB)/Ti composites by powder metallurgy and hot extrusion

• Published in: Materials & design Vol. 95; pp. 127 - 132
• Main Authors: Li, Shufeng, Kondoh, Katsuyoshi, Imai, Hisashi, Chen, Biao, Jia, Lei, Umeda, Junko, Fu, Yabo
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05-04-2016
• Subjects: Hot extrusion; In situ reaction; Mechanical properties; Metal matrix composites; Microstructure; Particulate composites; Powder metallurgy; Reinforcement; Strengthening; Titanium; Titanium carbide; Whisker composites; Titanium; Mechanical properties; Metal matrix composites; In situ reaction; Powder metallurgy; Microstructure
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2016.01.092

Titanium matrix composites (TMCs) reinforced with in situ-formed TiC particles and TiB whiskers were prepared by reacting titanium and B4C via powder metallurgy and hot extrusion. The effect of the in situ-formed TiC–TiB hybrid reinforcements on the microstructure and mechanical behavior of the TMCs was investigated. TiB whiskers exhibited favorable alignment, orienting parallel to the deformation axis after hot extrusion, while TiC particles and TiB whiskers were distributed homogenously throughout the extruded composites. The synthesized TMCs with a 13.6% volume fraction of TiC–TiB hybrid reinforcements presented a σUTS of 1138MPa, representing a 74% improvement compared to pure titanium, and retained an acceptable elongation of 2.6%. The synergistic strengthening effect of TiC particles and TiB whiskers was investigated via in situ tensile observations based on the load-transfer mechanism between the titanium matrix and TiC–TiB reinforcements.
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•Titanium matrix composites reinforced with In situ-formed TiC-TiB hybrid reinforcements were fabricated by reacting of Ti-B4C by powder metallurgy.•The synergy strengthening effect of TiC-TiB hybrid reinforcements was studied via in situ tensile observation.•TiB whiskers are prone to rupture by obstructing the migration of matrix grain during plastic deformation, while TiC particles are unsusceptible.