Abstract:
Porous (Al
6Si
2O
13+TiC)/Al
2TiO
5 composites were fabricated by pressless reaction sintering method with γ-AlOOH, TiO
2 as raw materials and adding different mass fractions of SiC whiskers (SiC
w). The effect of SiC
w mass fraction on the porosity and compressive strength of (Al
6Si
2O
13+TiC)/Al
2TiO
5 composites was analyzed, and the strengthening mechanism of SiC
w was discussed. The results show that, the product without SiC
w is composed of Al
2TiO
5, a small amount of Al
2O
3, and a few of unreacted TiO
2. After adding SiC
w, Al
6Si
2O
13 and TiC phases are formed. Moreover, TiC and Al
6Si
2O
13 exist in Al
2TiO
5 matrix mainly with regularly particles and whiskers morphology respectively. TiC particles and Al
6Si
2O
13 whiskers synergeticly reinforce composites by refining the microstructure, crack deflecting and whiskers bridging effects. Both porosity and compressive strength improve with the addition of SiC
w. With the increasing of SiC
w mass fraction, the porosity of (Al
6Si
2O
13+TiC)/Al
2TiO
5 composites decreases, but the increasing rate of compressive strength slows down gradually. When SiC
w mass fraction is 7.2%, the compressive strength is highest, which can reach 301.81 MPa.