The very high ignition pressures and temperatures in modern engine concepts present new challenges for the tribological system consisting of valve, valve seat insert, and valve guide. Lower exhaust gas emissions and reduced oil consumption requirements also contribute to making operating conditions tougher.
A crucial influencing factor here, for example, is the relative movement between the valve seat and the valve seat insert, which results on account of the elastic deflection of the valve plate under combustion chamber pressures up to 200 bar and more. The impact-like closure of the valve can be crucial for wear. MAHLE is continuously working on new materials for valve seat inserts and valve guides which can satisfy the increasing requirements. The combination of different alloy components with various properties - for example the self-lubricating effect of copper - enables precisely adapted material compositions to be achieved.