Accession Number : ADA254635


Title :   An Investigation of Residual Stresses in Machined Silicon Nitride


Descriptive Note : Final rept.


Corporate Author : ARMY LAB COMMAND WATERTOWN MA MATERIAL TECHNOLOGY LAB


Personal Author(s) : Snoha, Daniel J ; Foley, Michael R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a254635.pdf


Report Date : Jul 1992


Pagination or Media Count : 25


Abstract : An X-ray diffraction (XRD) residual stress investigation was conducted on groups of machined silicon nitride specimens utilizing copper K alpha radiation, the (323) 0-phase crystallographic planes and the sin2 psi stress-measuring technique. Cylindrical button-head tensile specimens formed by different processes and finish machined by different shops were characterized both before and after heat treatment. Surface machining stresses were also determined on a partial-machined tensile rod and on fractured flexure bars. The residual stress results are presented in the form of a comparative evaluation of processing parameters. Supplemental integrated intensity data from measurements on the partial-machined tensile rod and crushed buttonhead powder samples has demonstrated that XRD residual stress analysis may be applicable as a quality assurance procedure.


Descriptors :   *STRESS ANALYSIS , *MACHINING , *HEAT TREATMENT , *SILICON NITRIDES , *RESIDUAL STRESS , STRESSES , LAYERS , POWDERS , X RAY DIFFRACTION , X RAYS , SURFACES , QUALITY ASSURANCE , RODS , WIDTH , SILICON , COPPER , RESIDUALS , DIFFRACTION , QUALITY , CERAMIC MATERIALS , FINISHES , HEAT , PHASE , NITRIDES , INTENSITY , PROCESSING , PARAMETERS , MEASUREMENT , RADIATION


Subject Categories : Inorganic Chemistry
      Ceramics, Refractories and Glass
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE