STUDY OF ABRASION BEHAVIOR OF AN ADVANCED AL2O3-TIC-CO CERAMIC

In a newly developed chemical deposition process, a layer of metal cob alt film is coated on the surface of ultrafine ceramic powders of Al2O 3 and TiC. The mixture of the two kinds of Co-coated powder (about 70 wt.%Al2O3-Co + 30 wt.%TiC-Co) is hat-pressed into advanced Al2O3-TiC-C o (ATC) ceramic. Scanning electron microscopy observation is employed to investigate its abrasion behavior. Relatively soft SiO2 and hard Si C particles are used to study its abrasion wear resistance. Its high f racture toughness of 7.9 MPa m(1/2) and bending strength of 714 MPa ar e believed most important in making it more resistant than AT30 (Al2O3 + 30 wt.%TiC) ceramic under different loads and with different abrada nts. As well as the toughening effect, the refining and cladding effec ts of cobalt metal in the matrix also make a contribution to it. The h ardness of abrasion particles plays an important role in the test. It is showed that the worn surface appears smooth with partly plastic def ormation, together with the fracture surface indicating that single pa rticle and cluster spalling are the dominant mechanisms in the wear da mage of ATC ceramic. (C) 1997 Elsevier Science S.A.