《Oxidation of in situ synthesized TiC particle-reinforced titanium matrix composites》.pdf

Materials Science and Engineering A 404 (2005) 42–48 Oxidation of in situ synthesized TiC particle-reinforced titanium matrix composites Yexia Qin a,∗, Weijie Lu a , Di Zhang a , Jining Qin a , Bo Jib a State Key Laboratory of Metal Matrix Composites, Shanghai JiaoTong University, Shanghai 200030, PR China b Shanghai No. 5 Steel Co. Ltd., Bao Steel Group, Shanghai 200940, PR China Received in revised form 11 May 2005; accepted 19 May 2005 Abstract The oxidation behavior of TiC particle reinforced titanium matrix composites (TMCs) was studied in a temperature range 550–650 ◦C in atmosphere. The in situ oxidation observation at the very initial stage was investigated by high-temperature optical microscopy in air. The oxide layer of long-term oxidation behavior was examined by scanning electron microscopy (SEM) combined with an energy dispersive X-ray spectroscopy unit (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The oxidation kinetics follows a parabolic rate law. The oxidation rate decreases gradually as the oxidation proceeds. The oxidation of the composite took place firstly on Ti because of the higher reactivity of Ti and O2 than that of TiC and O2 . However, the TiC reinforcement can decrease the overall oxidation rate at 550, 600, and 650 ◦C. It is attributed to the formation of thin and dense oxidation, the enough strong interface cohesion between reinforcements and the titanium matrix alloy. © 2005 Elsevier B.V. All rights reserved. Keywords: High-temperature; Oxidation; In situ; Titanium matrix composites; Oxidation kinetics 1. Introduction out on in situ TMCs oxidation. It is necessary to investig