Fabrication,Microstructure and Mechanical Properties of TiC/Ti₂AlC/TiAl₃ in situ Composite

Lu Shi 1),Jianfeng Zhang 1),Lianjun Wang 2),Wan Jiang 1,2) and Lidong Chen 1) 1) State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Science,Shanghai 200050,China 2) State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University,Shanghai 201620,China

Õª Òª£ºThis paper described a process for synthesizing a new multiphase TiC/Ti2AlC/TiAl3 composite,in which Ti,Al4C3 and graphite powders were utilized as raw materials,and in situ spark plasma sintering-reactive sintering£¨SPS-RS£© methods were involved.The intermediate phases of Ti3Al and TiAl were found during the reactive sintering process and the reactions for the phase¡¯s formation were proposed.The microstructure and mechanical properties of the composites were investigated.The high-resolution transmission electron microscopy£¨HRTEM£© image of the interface showed that no amorphous phases were detected along the grain boundary.The orientation relationships between the Ti2AlC and the TiC were shown to be£¨0001£©Ti2AlC||£¨111£©TiC and [1ªÖ10]Ti2AlC||[110]TiC.The average hardness,fracture toughness,Young¡¯s modulus and bending strength of the composite were 15.1¡À0.8 GPa,4.9¡À0.3 MPa¡¤m 1/2,261¡À13 GPa and 776¡À18 MPa,respectively.The toughening mechanism was also discussed.

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