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Ceramic composites consist of zirconia toughened alumina (ZTA) with TiO2as additive was fabricated via solid state sintering route. Numerous studies have indicated that TiO2can be used as sintering additives for Al2O3and the ability of microstructural control introduce by TIO2. The Vickers hardness of the obtained ZTA-TiO2was evaluated as a function of different TiO2 addition. Each sample was dry mixed, uniaxially pressed and sintered at 1600 °C for 4 hours in pressureless condition. It is noticed that the presence of TiO2greatly influence the microstructure of Al2O3. Al2O3grains tend to increase in size with more addition of TiO2. Characteristics of Vickers hardness increases increases from 1516.13 HV (0 wt% TiO2) to 1615.8 HV (3 wt% TiO2). Addition of TiO2also increases the bulk density of ZTA-TiO2from 3.90 g/cm3(0 wt% TiO2) to 4.10 g/cm3(3 wt% TiO2).

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The zirconia toughened alumina enhanced with titania and chromia (ZTA-TiO2-Cr2O3) ceramic cutting tool is a new cutting tool that possesses good hardness and fracture toughness. However, the performance of the ZTA-TiO2-Cr2O3 cutting tool continues to remain unknown and therefore requires further study. In this research, the wearing of the ZTA-TiO2-Cr2O3 cutting tool and the surface roughness of the machined surface of stainless steel 316L was investigated. The experiments were conducted where the cutting speeds range between 314 to 455 m/min, a feed rate from 0.1 to 0.15 mm/rev, and a depth of cut of 0.2 mm. A CNC lathe machine was utilised to conduct the turning operation for the experiment. Additionally, analysis of the flank wear and crater wear was undertaken using an optical microscope, while the chipping area was observed via scanning electron microscopy (SEM). The surface roughness of the machined surface was measured via portable surface roughness. The lowest value of flank wear, crater wear and surface roughness obtained are 0.044 mm, 0.45 mm2, and 0.50 µm, respectively at the highest cutting speed of 455 m/min and the highest feed rate of 0.15 mm/rev. The chipping area became smaller with the increase of feed rate from 0.10 to 0.15 mm/rev and larger when the feed rate decrease. This was due to the reduced vibrations at the higher spindle speed resulting in a more stable cutting operation, thereby reducing the value of tool wear, surface roughness, and the chipping area.

The effect of single-wall carbon nanotube (SWCNT) addition on the physical properties of alumina (Al2O3) ceramic composite were studied in this paper. The SWCNT and Al2O3 nanocomposite samples were prepared using wet mixing with 5 different compositions of SWCNT. The nanocomposite samples were confined inside alumina sagger with high purity graphite packing powder and were sintered using pressureless sintering at 1600°C. The hardness shows an optimum values at 0.1 wt% of SWCNT, 20.13 GPa. However, further addition of SWCNT then reduced the properties values of the Al2O3.