Observation of Crack Growth Behavior of Various Cracks in 4.762mm Diameter Silicon Nitride Balls under Cyclic Compressive Load

Abstract

In order to investigate the effect of pre-crack lengths on strength of silicon nitride balls under cyclic pressure loads, growth behavior of 600~700μm pre-cracks were compared to those of 200μm~300μm and 400~500μm pre-cracks. Furthermore, the change in initial threshold limit of the maximum stress intensity factor was discussed. It was found that the increasing ratio of stress intensity factor during N=0 and N=1000 distinguished the failure and non-failure, and pre-crack length had strong effect on the threshold limits of the increasing ratio.

Observation of Mode I and Mode II Fatigue Crack Growth on Silicon Nitride Balls under Cyclic Compressive Loads

“…In this investigation, 4.762 mm (3/16 inch) diameter HIP-sintered bearing balls (TSN-03, Toshiba Materials Co., Ltd.) were used. The test jig was the same one used in our previous work [8]. Fig.…”

“…In our previous investigation, Kida et al [6] developed a fatigue test method using a silicon nitride ball. The fatigue crack growth in mode I under cyclic compressive loads was observed, and the effects of stress ratio [7] and length of pre-crack [8] on mode I fatigue crack growth were researched using this method.…”

Observation of Mode I Crack Growth Behavior in 4.762 mm Diameter-Silicon Nitride Ball under Compressive-Tensile Cyclic Loadings

“…In this work, pre-cracks inducement and fatigue tests were conducted using the ball holding jig reported in our previous paper [9]. The ball holder consists of plates, tightening bolts, and bars (hardened JIS-SUJ2).…”

Effects of Loading Magnitude and Fatigue Crack Growth on Crack Opening-Closing Behavior on Silicon Nitride Ball under Cyclic Compression

“…[8]. The test jig which Toriki developed [9] was used in this test. To obtain the compressive load during observations, strain was measured by the strain gages put on the SUJ2 bars as shown in Fig.…”