Preparation, Microstructure And Properties Of Ti₃SiC₂Bonded Corundum Materials

Ti3SiC2material possesses many excellent attributes of metals and ceramics, suchas high strength, high melting point, good oxidation resistance, good thermal shock,high fracture toughness, easy machinability and other excellence performances. Becauseof these better properties mentioned above, it is expected to apply in various fields. Inorder to make full use of the excellent properties of Ti3SiC2material, Ti3SiC2bondedcorundum materials were prepared to avoid the harms caused by oxidation ofcarbon-containing refractory, to purity molten steel and improve the service life. Inaddition, Ti3SiC2improves the toughness and machinability of corundum, to developcontinuous casting refractories with multi functions, excellent properties and extendedservice life.In this paper, Ti3SiC2bonded corundum materials were prepared using tabularalumina as aggregate, two kinds of raw powder systems: TiC/Ti/Si, TiC/Ti/SiC asmatrix, and phenolic resin as binder, firing at1350-1550℃in Ar atmosphere. Theinfluence of raw material system, firing temperature and matrix formulations on phasecomposition, microstructure and room temperature physical properties of Ti3SiC2bonded corundum samples were investigated. Furthermore, the effect of penolic resinaddition, PVA instead of penolic resin as a binder, the particle size distribution, Alpowder addition on fundamental properties of Ti3SiC2bonded corundum materials arestudied. The results showed:（1）When Ti3SiC2bonded corundum materials were sintered using two kinds ofraw material systems, the main phases of samples were Al2O3, Ti3SiC2and TiC. Whenfiring at1350-1400℃, the samples of two kinds of raw material systems possessed high compressive strength. With increasing firing temperature, the compressive strength ofsamples decreased. The samples prepared with TiC/Ti/Si gained the best performancewhen firing at1400℃for6h, Ti3SiC2content in the matrix reached64%, thecompressive strength of samples were65MPa.（2）With the increase of Al2O3addition in matrix, Ti3SiC2content of samples firstincreased, but decreased when Al2O3content was more than10%. The maximum was71%. In addition, when Al2O3powder increased, the apparent porosity of samplesincreased, and the compressive strength of samples decreased.（3）When penolic resin addition was4.5%, the physical properties of Ti3SiC2bonded corundum samples were the best. Ti3SiC2content in the matrix reached65%,the apparent porosity of samples was24%, the compressive strength were72MPa.（4）Using PVA instead of penolic resin as a binder, Ti3SiC2content of samplesobviously increased. However, the apparent porosity of samples increased, and thecompressive strength decreased.（5）With the increase of fine powder addition in the particle size distribution, thecompressive strength of samples increased.（6）Al powder addition can accelerate the synthetic of Ti3SiC2and grain growth,as well as increase the purity of samples. However, with the increase of Al powderaddition, the compressive strength of samples decreased.