For years the chromium ceramic coating has proved to have good resistance when applied for Diesel engines subjected to severe operational conditions. However, given the constant increase of engine demands and the concern of low gas emissions, higher wear resistance and durability have been required.
As a consequence, MAHLE has developed a new chromium-based coating, which balances the cost competitiveness of chromium-based coatings with enhanced performance.
The new coating, named NanoBor Chromium, consists of reinforced chromium coating with ultrafine cBN particles (cBN = cubic boron nitride) embedded inside micro-fissures created by a controlled multi-stage electrochemical process.
The tests in MDD engines (MDD=Medium-duty diesel) and HDD engines (HDD= Heavy-duty diesel) have demonstrated the excellent performance of NanoBor Cr as new alternative for heavily demanded application.
Besides the performance results of rig tests for wear resistance, this paper also presents the performance evaluation in durability engine tests in two different Diesel engines application and in an abusive scuffing engine test.