## 3 Results and Discussion  
### XRD Phase Composition Diagram of the Ceramic Material  
The XRD (XRD is the abbreviation of X-Ray Diffraction) diffraction analysis of the ceramic material with 6 vol% ZrO\({}_{2}\) whisker and 10 vol% nano coated CaF\({}_{2}\)@Al(OH)\({}_{3}\) powder is shown in Figure 2. In the ceramic material, the phase analysis indicates that the predominant phases for the composites are Ti(C,N) and Al\({}_{2}\)O\({}_{3}\). Before the experiment, the ZrO\({}_{2}\) whisker exists in monoclinic phase. From Figure 2, it can be seen that ZrO\({}_{2}\) exists mainly in the form of t-ZrO\({}_{2}\) in the ceramic material. This indicates that the phase transition took place during the sintering. The ZrO\({}_{2}\) whisker underwent a phase change. The introduction of nano coated powder does not have a significant influence on it, which provides the fundamental condition for the phase transition toughening. The presence of the characteristic peak of CaF\({}_{2}\) is clearly observed. In this paper, the addition of sintering aid MgO is 0.5 vol%. The characteristic peak of MgO is not observed, because the addition amount of MgO is too small. The chemical composition of the various components constituting the composite ceramic has a good chemical compatibility, and an obvious chemical reaction does not take place. Influence of ZrO\({}_{2}\) Whisker Addition on Al\({}_{2}\)O\({}_{3}\)Ti(C,N) Ceramic Material  
Figure 3a-c represents the scanning electron microscope photographs of the fracture surfaces of the Al\({}_{2}\)O\({}_{3}\)/Ti(C,N) ceramic material with 3 vol%, 6 vol% and 9 vol% ZrO\({}_{2}\) whisker, respectively. It can be observed that the grains are coarser in Figure 3a or Figure 3c. However, the grains in Figure 3b are finer than those in Figure 3a and the uniformity of Figure 3b is improved. The addition of the ZrO\({}_{2}\) whisker has an influence on the grain refinement of the ceramic material, and the ZrO\({}_{2}\) whisker can suppress the abnormal growth of the crystal grain. When the addition of the ZrO\({}_{2}\) whisker is 9 vol%, more pores can be seen in the cross section. A possible reason for this is that under the process conditions selected by the experiment, the dispersion of the ceramic material with 9 vol% ZrO\({}_{2}\) whisker may not achieve the desired effect, contributing to the bridging or agglomeration of the whisker. The occurrence of pores leads to a decrease in the relative density. Due to the contrast, less pores can be seen in the cross section when the additive amount ZrO\({}_{2}\) whisker is low. The existence of pores influences the densification of the ceramic material and thus reduces the mechanical properties of the ceramic material. Whisker reunion can be found in Figure 3c mark 1, and the whisker section can also be observed by magnification, as showed in Figure 3d. The consequences of adding 0, 3 vol%, 6 vol% and 9 vol% ZrO\({}_{2}\) whisker on the mechanical properties of the Al\({}_{2}\)O\({}_{3}\)/Ti(C,N) ceramic material are shown in Figure 4. The ceramic material without ZrO\({}_{2}\) whisker has a high hardness of 20.47 GPa. With the increasing addition of ZrO\({}_{2}\) whisker, the hardness is prone to decrease. When the addition of ZrO\({}_{2}\) whisker increases, the flexural strength of the ceramic material increases significantly from 555 to 584 MPa. Whereas when the additive amount of ZrO\({}_{2}\) is more than 6 vol%, the flexural strength of the ceramic material shows a decreasing trend. The ceramic material obtains maximum flexural strength when the ZrO\({}_{2}\) whisker addition is 6 vol%. With the increase in ZrO\({}_{2}\) whisker addition, the fracture toughness also shows an increasing trend. It reveals that the introduction of ZrO\({}_{2}\) whisker can enhance the fracture toughness of the material. The ceramic material without ZrO\({}_{2}\) whisker has the highest relative density. With the addition of ZrO\({}_{2}\) whisker increasing, the relative density decreases first and afterward increases.