The Role Of The Grain Boundary In The Deformation Of Ceramic Materials, Part II.

Item

Title
The Role Of The Grain Boundary In The Deformation Of Ceramic Materials, Part II.
Date
1963
Index Abstract
Coming Soon
Photo Quality
Complete
Report Number
ASD TDR 62-225 Part 2
Creator
Murray, G. T.
Mountvala, A. J.
Corporate Author
Materials Research Corporation
Laboratory
Directorate of Materials and Processes
Extent
32
Identifier
AD0407069
Access Rights
OTS
Distribution Classification
1
Contract
AF 33(616)-7961
DoD Project
7350
DoD Task
735003
DTIC Record Exists
No
Distribution Change Authority Correspondence
None
Abstract
The mechanical behavior of MgO grain boundaries at elevated temperatures was investigated. The shear strength of bicrystal specimens was ob tained (constant loading rate tests) at 1400 C for a wide range of crystal misorientations. Large twist, low tilt boundaries fractured at extremely low stress compared to other misorien tations. For a given tilt angle the fracture stress decrease th increasing twist component; the decrease being sharper for low tilt bound aries and more gradual for boundaries possessing large tilt components. The effect of temperature on the grain boundary fracture stress was inves tigated for varying misorientations in the range 1200 - 1500 C. For each type of boundary orien tation there was a characteristic temperature where there was a sudden drop in strength, this transition temperature being lowest for bound aries with a high twist component. Experiments on tricrystals indicated that the weaker twist type boundaries controlled the fracture strength of the entire body.
Report Availability
Full text available
Date Issued
1963-03
Provenance
Lockheed Martin Missiles & Fire Control
Type
report
Format
1 online resource
Media
ASDTDR62-225part02.pdf