Effects of temperature upon the thermophysical properties of materials for sintered guides of internal combustion engine valves

Conclusions

• 1. It was established that the thermal conductivity of sintered iron base materials is one-half that of pure iron produced by casting and about the same as that of an ordinary cast iron. Post-sintering annealing resulting in a granular pearlitic structure lowers their thermal conductivity by about 10%, while sulfidizing raises it by the same amount. With rise in temperature, the thermal conductivity of all these materials falls.

• 2. The specific heat of all the materials investigated is approximately equal to, and in some cases slightly higher than, that of pure iron.

• 3. The coefficients of linear expansion of the three materials investigated, which are almost identical, are similar to those of cast carbon steels (see, for example, [5]) and some 15% higher than that of pure iron.

• 4. The sintered iron base materials investigated have thermophysical properties comparable to those of antifriction cast irons, and can be recommended as materials suitable for valve guides and other components of internal combustion engines operating under friction conditions.