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Using spark plasma sintering(SPS)technique,TiC particle reinforcedγ-TiAl composites were prepared with varying weight fraction of TiC powders.The effects of the TiC fractions and distributions on the properties of the composites were investigated.The composite containing 7wt%TiC had the optimum three-point bending strength of 842 MPa,which was 200 MPa greater than that of the unreinforcedγ-TiAl intermetallic.The degradation of the bending strength occurred in the composites containing more than 7wt% TiC and this was believed to be attributed to agglomerated particles of TiC,which acted as crack initiation and propagation sites.The increase of strength in TiC reinforced IMCs came from the grain refinement and the interaction of dislocations with the reinforcing particles.The bending strength of the IMC containing 7wt% TiC was theoretically estimated to increase by 85 MPa and 200 MPa,respectively,by the grain refinement and dislocation strengthening,the total of which was almost in accordance with the improvement in that of the unreinforcedγ-TiAl intermetallic when considering normal estimation errors.
Using spark plasma sintering (SPS) technique, TiC particle reinforced γ-TiAl composites were prepared with varying weight fraction of TiC powders. The effects of the TiC fractions and distributions on the properties of the composites were. The composite containing 7 wt% TiC had the optimum three-point bending strength of 842 MPa, which was 200 MPa greater than that of the unreinforced gamma-TiAl intermetallic. the degradation of the bending strength occurred in the composites containing more than 7 wt% TiC and this was believed to be attributed to agglomerated particles of TiC, which acted as crack initiation and propagation sites. the increase of strength in TiC reinforced IMCs came from the grain refinement and the interaction of dislocations with the reinforcing particles. bending strength of the IMC containing 7wt% TiC was theoretically estimated to increase by 85 MPa and 200 MPa, respectively, by the grain refinement and dislocation strengthening, the total of which was almost in acc ordance with the improvement in that of the unreinforced γ-TiAl intermetallic when considering normal estimation errors.