Edge distance is the main factor inducing edge chipping. An edge chipping experiment is designed to study the relationships between edge distance and the edge chipping from the aspect of fracture process, the load-displacement curves and AE signals are documented. The results show that the fracture processes of edge chipping at different edge distances are similar and could be divided into four stages, AE signals could reflect the fracture process features of edge chipping. As edge distance increases, the displacements of indenter and critical loads would increase correspondingly, while the peak values of count and duration would decrease. The critical edge distance for Al2O3 is about 0.75mm; the displacements of indenter would keep invariable, while the peak values of count and duration would get to the minimum.

To study the failure process of edge chipping for engineering ceramics, a method of energy analysis is used. Acoustic emission parameters such as energy, cumulative energy and amplitude collected in the experiment system are analyzed in this paper. The results show that energy and cumulative energy change little, amplitude changes among 40dB to 60dB before fracturing; the main reason for these is the micro-cracks propagation. While edge chipping engenders, energy, cumulative energy and amplitude would increase sharply and reach to the maximums; the main reason for these is the macro-cracks coming into being, and lots of energy release out. The change regulars of different parameters have reflected types of acoustic emission source. The method of energy could reveal the fracture mechanism of edge chipping for engineering ceramics well.

Three cutting tools, YG610, Si3N4 ceramic tool and CBN were adopted for heat cutting deposited materials. The test results show that though the impacts to the tools reducing, the CBN still break seriously. The condition by Si3N4 ceramic tool is better than CBN, whose types of tool failure change from breakage to wear. The YG610 is best material for heat cutting, whose minimum VB value is only 0.3mm. In the experiment, the wear increase with the increasing of heating temperature, cutting speed, cutting depth. But it decreased with feed rate. The analysis results show that the red-hardness is most importance factor for wears of YG610.

Ceramic plunger couple are appreciated by engine designer thanks to its high performances such as anticorrosion and wearproof, however which are restricted due to machining difficulty. This article will discuss the feasibility of replacing metal material with silicon nitride ceramics in plunger coupler manufacturing through analysis on change law of stress and displacement of 12150L diesel engine plunger coupler at rated condition, design and develop special clamp for intractable spiral line and oil-out trough, and with satisfactory machining effect.

The developments of edge chipping for engineering ceramics are analyzed. An edge chipping experiment under static load is adopted to study the fracture process of edge chipping. The results show that the fracture processes of edge chipping under different edge distances are similar, which can be divided into four stages based on load-displacement curve. There is obviously Kaiser Effect during the fracture processes of edge chipping. Counts, average frequency, RMS, duration, amplitude and inverse calculation can be used to describe the process of edge chipping for engineering ceramics. Amplitude, duration and average frequency become highly active on the eve of fracture, which can be regard as the omens of edge chipping and used to predict the fracture of edge chipping.