Study of Erosion Mechanisms of Engineering Ceramics.
Abstract
Four 'engineering' ceramics were subjected to impact (single particle) and erosion (multiple impacts) under conditions which simulate a natural dust environment in the subsonic velocity regime. The target materials are hot pressed Si3N4, reaction bonded Si3N4, glass bonded Al2O3 and hot pressed MgF2. Tests were performed with 6 narrow size ranges of natural quartz between 10 and 385 microns average, and 5 velocities for each particle size. Hot pressed Si3N4 was also impacted with SiC under the same particle size velocity conditions. The results are discussed in terms of current erosion and impact models by considering particle size-velocity dependencies, appearance of the impact damage, and the basic properties and structure of the targets. Under these erosion conditions, the four target materials exhibited widely different behavior not only in absolute amount of material removed, but also in mechanism of removal. The systems hot pressed Si3N4-SiC particles and MgF2-quartz particles were characterized by plastic impact with associated lateral and radial crack formation, and erosion loss was proportional to particle mass and velocity to the fourth power. Erosion of hot pressed Si3N4 impacted with quartz particles was proportional to the first power of particle size and velocity, and loss occurred by minor chipping with no secondary crack formation. Erosion of glass bonded Al2O3 and reaction bonded Si3N4 did not show a consistent particle size-velocity dependence. The variation is related to the two phase structure of these materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1977
- Accession Number
- ADA045216
Entities
People
- Mary Ellen Gulden