小球衝突試験装置の試作とセラミックスの破壊強度評価

概要

論文の詳細を見る
The application of structural ceramics to gas turbine components is currently expected as a means of improving peformance. Due to its low toughness, however, an assessment of the resistance against damage caused by foreign objects is requied. In order to investigate the damage caused by impact from a projectile, we tentatively fabricate a particle impact test rig, which is a gas-gun-type accelerator operated with air or helium gas. It can accelerate projectiles up to a velocity that is almost equal to the speed of the tip of a gas tubine moving-blade. In this study, the single -particle fracture test for four kinds of materials was made on this test rig. Two types of fracture modes were obsreved. One is the fracture with cracks propagating conically from the contact point and the other is that with the cracks propagating radially from the opposite side of the impact location. The critical velocity of each fracture mode is explained as a function of projectile size, target thickness and mechanical properties such as flexural strength or fracture toughness. Furthermore, from the viewpoint of practical operation, the influence of compressive stress field on critical velocity is discussed.
一般社団法人日本機械学会の論文
1994-02-25