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A STUDY ON STRENGTH CHARACTERISTICS OF Si 3 N 4 COIL SPRINGS
Author(s) -
Sato S.,
Taguchi K.,
Adachi R.,
Nakatani M.
Publication year - 1996
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1996.tb00989.x
Subject(s) - electromagnetic coil , coil spring , materials science , volume (thermodynamics) , composite material , ceramic , structural engineering , engineering , spring (device) , thermodynamics , electrical engineering , physics
— Coil springs made of silicon nitride (Si 3 N 4 ), which has higher strength and heat resistance than other ceramics, have recently been developed. By examining the range of strengths and the heat resistance of the coil springs, it is shown that the coil springs can be used at temperatures up to 1000°C. We derive an equation to calculate the effective volumes of coil springs and examine the influence of size on the strength of coil springs. In addition, using a process zone size failure criterion, proof tests were conducted and analysed. The results show that the mean strength of coil springs decreases with increasing effective volume. Therefore the strength of coil springs can be estimated from the value of the effective volume, and this relationship can be applied in design calculations. Furthermore, by conducting proof tests, coil springs that have relatively large defects can be eliminated and so only highly reliable coil springs can be placed in service.