Thermal aging, effect

Although polycarbonate is exceptional among engineering resins in exhibiting an outstanding level of toughness, its ductile-brittle transition depends on the temperature, notch sharpness, sample thickness and thermal aging effects. A sharp ductile-brittle transition [Carhart, 1985] for polycarbonate occurs at 0-10°C, hence its... 

T. J. Dunyak, D. R. Chang, and M. L. Millard. Thermal Aging Effects in Oxide/Oxide Ceramic Matrix Composites, NASA. Conference Publication, [No. 3235, pt. 2] pp. 675-89 (1994). 

Dlouhy, Z. Chlup, D. N. Boccaccini, S. Atiq, A. R. Boccaccini, Fracture Behaviour of Hybrid Glass Matrix Composites Thermal Ageing Effects, Composites Part A 34, 1177-1185 (2003). 

Note that the unprotected circuits of the control had substantial drift of the three that did not fail during the test run. Failures were evident upon inspection of the part as occurring from disintegrated resistors. Dip coated PSS and HMDS had fewer failures and less drift. The best protection from moisture was offered by the plasma-polymerized HMDS. The indicated 1.7% drift is close to the acceptable limits of the design for power-on thermal aging effects. 

Simnazcelik, T. and Ydmaz, T. (2007). Thermal aging effects on mechanical and tribological performance of PEEK and short fiber reinforced PEEK composites. Materials Design 28, 641 -648. 

Cracks have been discovered in cast primary pump bodies, valves and elbows in main circulation loops. Dye penetrant testing revealed a number of cracks. The cracks were found both on the inside and on the outside of the casings. Moreover, the duplex austenitic-ferritic structure of cast steel pipes used in some NPPs is a potential cause of an embrittlement due to the thermal ageing effect on the ferritic part. It is difficult to perform reliable volumetric non-destructive testing by ultrasonic techniques of the cast material. 

The use of cast austenitic stainless steel is minimised in the AP1000 reactor internals. Where used, cast austenitic stainless steel is limited in carbon and ferrite contents, and is evaluated in terms of thermal aging effects (Section 4.5.2.1 of Reference 6.1). 

P. (2008) Catalytic decomposition of N2O on supported catalysts support and thermal ageing effects on the catalytic performances. Catal. Today, 137, 390-3%. 

J.P. Stephens, Thermal Aging Effects in Refractory Metal Alloys, NASA Technical... 

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