Heat - and Wear-Resistant Nanocomposite Material Based on Copper Powder for Valve Guides of High-Forced Engines

Abstract

The article presents the results of the development of heat - and wear-resistant nanocomposite material based on copper powder Cu-Al-C-O system, which due to the optimally selected chemical composition and dispersion-strengthened structure with a strengthening phase γ-Al2O3 of nanodispersed range has a set of physical, mechanical and operational characteristics, at its level significantly higher than the similar characteristics of the standard bronze CuNi2Si F65 DIN 17666, used by a number of engine companies for the valve guides of powerful and high-forced internal combustion engines. In particular, the wear resistance coefficient for the valve guide made of this material is 17 times higher than for the guide made of this standard bronze. In this case, the coefficient of score-resistance of the bushings of the new material is 2.54 times higher than the same index for the bushings of bronze. Moreover, it also provides the least wear not only of the guide bushing but also of the valve, i.e. of the entire pairing as a whole.

Optimization of Dispersion-Strengthened Material Based on Copper Powder for Valve Guides of Internal Combustion Engines

“…The main purpose of valve guides of internal combustion engines is taking lateral loads acting on the valve stem. In case of valve guide misalignment with respect to the valve stem the contact pressure in the place of their contact can exceed 100 MPa [2], which most often leads to valve sticking in the guide. The valve guide, apart from aligning the valve head on the valve seat, also performs functions of heat transfer from the valve head through the valve stem to the cylinder head.…”