| SiAlON is one of the most promising high temperature structuralmaterials, because of its excellent high temperature strength, goodthermal shock resistance, good resistance to creep at high temperature,good resistance to corrosion and low density. However, the intrinsicbrittleness of the cermets limits its application. In this paper, We havebeen used metal-composition a technologies to Strengthening on theSiAlON cermerts. to obtain a homogeneous metal distribution and toimprove the interfacial wettability between the phase of metal andceramic.During preparation process of the powders, sinteringdensification, microstructure evolution, and its strengthening mechanismshave been investigated. The following some important and creativeconclusions have been obtained:1、The microstructure evolution and fracture mechanism of SiAlONcermet were studied during high-temperature sintering. The results showthat during the sintering process, With the Z value increases when theceramic grain shape by the multi-folded sheet into a hexagonal columnarcrystal grains of high aspect ratio intact.When the Z value2, due to thelarge pores and tabular grain material appears. The mechanical propertiesof the SiAlON ceramic has been distoryed.2、Mechanical properties of various atmospheric sintering Z cermetchanges with the law. With the Z value increases ceramic density, flexuralstrength and fracture toughness phenomenon occurs first increases andthen decreases.The effects of the high-temperature sintering process onthe SiAlON ceramic have been investigated. When the Z value0.9,roaring to1750℃for1h. The optional sintering density of the SiAlONcermet is3.29g/cm3, the flexural strength is910MPa, Vickers hardness is1530and fracture toughness is8.10MPa.m1/2.3、The tool life,failure patterns and mechanisms of SiAlON ceramichave been investigated.The results showed the composite value Z caneffect the life of tool and the main failure mechanisms tool has abrasivewear, adhesive wear, notch wear and chipping. |
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