Accession Number : ADP006824

Title :   The Effect of Heat Treatment on the Properties of Peek and APC-2,

Corporate Author : MIDDLE EAST TECHNICAL UNIV ANKARA (TURKEY)

Personal Author(s) : Ankara, A. ; Kalay, G. ; Folkes, M. J.

Report Date : APR 1992

Pagination or Media Count : 7

Abstract : This paper examines the effect of certain heat treatments on the properties of PEEK and carbon fibre reinforced PEEK. Differential scanning calorimetry, wide angle X-ray diffraction, dynamic mechanical testing, flexure testing and microscopy were done to study the changes in the amount of crystallinity and to observe the effect this crystallinity change on the other properties. DSC thermograms showed that although there is no considerable change in crystalline melting point of the composite specimens depending on the heat treatment applied there is a change in PEEK. It was confirmed by both DSC and WAXD data that it is possible to control crystallinity of PEEK and APC-2 easily by applying simple heat treatments. The glass transition temperatures of as-received PEEK and APC-2 obtained from dynamic mechanical spectrum are 165.90 and 160.90 C respectively. More higher glass transition temperatures were also observed for high % crystalline composite specimens. In the literature 1430 C is stated as Tg of these materials. The frequency effect on dynamic mechanical spectrum was also determined. It is concluded that as the frequency decreases the dynamic mechanical spectrum shifts to lower temperatures and loss tangent (tan delta) increases in value. Flexure testing results shows that the flexure properties are independent of crystallinity. Fracture surface examination was confirmed the debonding in quenched APC-2 samples. It was also observed strong adhesion for crystallized samples. This research clarifies the use and applicability of heat treatment for commercial processing.

Descriptors :   *FIBER REINFORCED COMPOSITES, *FLEXURAL STRENGTH, *MILITARY AIRCRAFT, ADHESION, ANGLES, CALORIMETRY, CARBON, DIFFRACTION, DYNAMICS, FREQUENCY, GLASS, HEAT, HEAT TREATMENT, MELTING POINT, MICROSCOPY, SCANNING, SURFACES, TEMPERATURE, TRANSITIONS, WIDE ANGLES, X RAY DIFFRACTION, TEST AND EVALUATION, FRACTURE(MECHANICS), CARBON FIBERS, CRYSTALLIZATION, FAILURE(MECHANICS), REPRINTS, NATO.

Subject Categories : Laminates and Composite Materials
      Aircraft
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE