Materials thermal fatigue

Veronski A, Hejwowsld T (1991) Creep-resisting materials. Thermal fatigue of Metals. CRC Press, p 81-93... 

Highly ductile materials tend to be more resistant to thermal fatigue and also seem more resistant to crack initiation and propagation. 

The insulation around the central electrode is an example of a non-metallic material - in this case, alumina, a ceramic. This is chosen because of its electrical insulating properties and because it also has good thermal fatigue resistance and resistance to corrosion and oxidation (it is an oxide already). 

But they all oxidise very rapidly indeed (see Table 21.2), and are utterly useless without coatings. The problem with coated refractory metals is, that if a break occurs in the coating (e.g. by thermal fatigue, or erosion by dust particles, etc.), catastrophic oxidation of the underlying metal will take place, leading to rapid failure. The unsafeness of this situation is a major problem that has to be solved before we can use these on-other-counts potentially excellent materials. 

Pompe, W.E. (1993), Thermal shock behaviour of ceramic materials - modelling and measurement , in Schneider, G.A. and Petzow, G. (editors), Thermal Shock and Thermal Fatigue Behavior of Advanced Ceramics, Dordrecht Kluwer Academic, 3-14. 

Gao, M., Dunfee, W., Miller, C., Wei, R. P., and Wei, W., Thermal Fatigue Testing System for the Study of Gamma Titanium Aluminides in Gaseous Environments, in Thermal-Mechanical Fatigue Behavior of Materials, Vol. 2, ASTM STP 1263, M. J. Verrilli and M. G. Castelli, eds., American Society for Testing and Materials, West Conshohocken, PA (1996), 174-186. 

The CVI SiC/SiC composites are also promising for nuclear applications because of the radiation resistance of the p phase of SiC, their excellent high-temperature fracture, creep, corrosion and thermal shock resistances. Studies on the P phase properties suggest that CVI SiC/SiC composites have the potential for excellent radiation stability [5]. Furthermore, because of excellent thermal fatigue resistance, start-up and shut-down cycles and coolant loss scenarii should not induce significant stmctural damage [5]. The CVI SiC/SiC are also considered for applications as stmctural materials in fusion power reactors, because of their low neutron-induced activation characteristics coupled with excellent mechanical properties at high temperature [6-8]. 

---