MACHINING HIGH PURITY ALUMINA.
Abstract
It was demonstrated that a pre-selected commercial grade, high-purity alumina (96%) can be made friable by immersion in aqueous hydrofluoric acid (52%) so that it can be machined with conventional cutting tools and then reconstituted to acceptable physical characteristics, i.e., dimensional control, porosity (open and closed pores), water absorption and a high pressure fuchin dye penetration. Further it has been demonstrated that a pre-selected, presently available commercial grade 96% alumina fired at cone 31 (1680 C) can be reconstituted at cone 33 (1745 C) to a purity level suggestive of approaching the theoretical density of alpha corundum (4.00). A basis is given for aiding in the selection of those alumina bodies which are most apt to accommodate to this new technique. Also, it is concluded that for optimizing this process, it might be well to design a body formulation which will adapt itself to this process rather than make use of existing bodies. Factors other than chemical composition, such as the primary raw material grain size and fired grain size, must also be considered. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1965
- Accession Number
- AD0624484
Entities
People
- J. M. Infield
- P. A. Marshall Jr.
- S. J. Beyer