THE YOUNG'S MODULUS AND INTERNAL FRICTION OF POLYCRYSTALLINE MGO AT ROOM TEMPERATURE
Abstract
Hot pressing method was used to prepare polycrystalline MgO from several starting powders, which behaved distinctly from each other. A direct relationship between the activity of the powder and its compressibility was found. As the density of the specimen increased the Young's modulus increased linearly, whereas the internal friction decreased. It was found that t e internal friction was inversely proportional to the square of t e grain diameter. Mg specimen of the same density, but from different origin may not necessarily have the same Y ung o ulus r internal riction values; t e e differences may be attributed to the presence of foreign atoms. (A UTHOR)AD - +) <%$( AD-270 255Div. 25, 14U (TISTM/GEC) New York tate Coll. of Ceramics, Alfred U. ULTRAVIOLET, VISIBLE, AND INFRARED TRANSMISSION IN MAGNESIA, by Rino Hanna and W. B. Cran all. 7 Jan 62, 6p. illus. tables, 9 refs. (Rept. no. 2) (Grant no. DA-ORD-31-124-60-G58) (AROD rept. no. 2891:2) Unclassified report No automatic release to Foreign Nationals. DESCRIPTORS: (*Ceramic materials, *Mag nesium compounds, *Oxides, Single crystals, Crystals, Optics, *Light transmission, Ultra violet radiation, Infrared radiation, Thick ness.) Optical absorption measurements were made rom 0.34 to 13 microns on single crystal and polycrystalline MgO. The polycrystalline samples were prepared by hot pressing to theoretical density. Two different types of this polycrystalline MgO are described, both types being translucent in the visible region. Two largeABSORPTION BANDS WERE OBSERVED IN BOTH THE SINGLE CRYSTAL AND POLYCRYSTALLINE MATERIAL ; THE FIRST AT ABOUT 11 MICRONS AND THE SECON AT A OUT 12.7 MICRONS. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1961
- Accession Number
- AD0270254
Entities
People
- Richard Hanna
- W.b. Crandall
Organizations
- New York State College of Ceramics