Ceramic cutting tools have been widely used as the preferred cutting tool  for the past century and continue to be used for machining in hard and difficult to cut materials such as alloy steel . The reasons are because of their outstanding properties, such as wear resistance, shock resistance, and high hot hardness [3–9]. Moreover, alumina (Al2O3) based cutting tools are the most frequently used ceramics in machining hard materials [7–8] and have been a desirable choice to improve the quality of products and minimise the costs of manufacturing and production time . This is due to its unique intrinsic properties, ideal for the cutting tool . Additionally, it possesses high hardness, high wear resistance, and excellent abrasion resistance [5, 12]. However, alumina-based cutting tools are vulnerable to thermal cracking . As such, zirconia (ZrO2), is added to Al2O3 to form zirconia toughened alumina (ZTA) [14–17]. ZTA is known to be more affordable and eases the fabrication process . Also, given its advantageous mechanical properties, it is commonly recognised as a tool material having high hardness, high-temperature strength, and able to sustain the shape of the cutting edge at higher temperatures . In order to enhance ZTA’s properties, such as fracture toughness and hardness, the additives are introduced into the ceramic compositions [18–19].
One of the additives used in this research is titania (TiO2), given some reports stating that the sintering temperature of ZTA ceramic materials was scarcely maintained and achieved . Indeed, with the addition of TiO2, the sintering temperature of alumina can be reduced . Despite that, TiO2 also improved the sample's mechanical properties in providing resistance to abrasive wear and high-temperature erosion corresponding to high thermal shock resistance . Furthermore, a research study stated that the density value increased as Vickers hardness increased due to the addition of TiO2 as an additive . However, further addition of TiO2 resulted in a minor increment of the values mentioned, where the value of the density is directly related to the Vickers hardness . The highest bulk density, flexural strength, and hardness can be achieved with the combination of ZTA - 4% TiO2 . It is also found that the growth of the grain in the ZTA-TiO2 composition was suppressed by the TiO2 grain refiner up to 4% of TiO2 addition and increases when the value exceeds 4%.
Furthermore, chromia (Cr2O3), is also used as an additive and has attracted increasing attention given its great ability to replace coated carbide or carbide itself . Also, due to the addition of Cr2O3, grain growth can be observed in the optimum state. The density, fracture toughness, and Vickers hardness value of the sample also increased. This finding is supported by a study where the highest value could be obtained by adding 0.6 wt.% amount of Cr2O3 . The author also mentioned that the interaction between the crack and the matrix grains improved by creating large plate-like grains. The strength increased due to grain deflection caused by the inter-granular fracture mode where cracks were dispersed along the grain’s borders. Moreover, the isovalent solid solution is developed due to the composition of the chromia doped in alumina , mainly because both are in a similar corundum crystal and sesquioxides. Additionally, the Cr2O3 additives also affected the microstructure of ZTA due to the larger grains and resulted in the increment of fracture toughness.
During the machining process, the ceramic cutting tool undergoes fracture, cracking, and ladder-like chipping due to low toughness [23–25]. Therefore, for improved performance, a fabricated cutting tool can be accomplished by compacting the specific composition of ceramic powders with other reinforced materials . However, the lack of toughness and high brittleness of the Al2O3 cutting tool can cause premature chipping at the edge of the tool [27–29]. Research of the microstructure and optimisation of machining parameters for ZTA-Cr2O3 has been reported by evaluating the composition's hardness and fracture toughness . This combination can perform at high cutting speed and has excellent ability to replace coated carbide or carbide. However, even though the good properties of ZTA-TiO2-Cr2O3 have been reported, the performance of the ZTA-TiO2-Cr2O3 cutting tool remains unknown and requires further study. In addition, a detailed study on the wear of this cutting tool is needed to demonstrate and prove the performance of the tool.
Accordingly, this research focuses on the newly developed cutting tool, ZTA added with TiO2 and Cr2O3. As such, the wearing of the ZTA-TiO2-Cr2O3 cutting tool and the surface roughness on the workpiece surface will be examined in this research. Three types of tool wear were analysed, and the surface roughness of the machined surface, determined by the Ra value. It is anticipated that this study will contribute and extend previous research by developing a ceramic cutting tool in the steel cutting industry.