Executive Summary :
Objective: To develop super hard nanocomposite coatings of transition metal nitrides /carbides eg: CrN-MoN-SiN, CrN-MoN-SiC etc., onto Automotive Chain Pins/ Cutting tools; To understand the performance of these coatings in relevant environment (Operation of Engine at LG Balakrishnan and Bros., Coimbatore and VS Tooling, Coimbatore)
Summary: (a) The driving chains or conveyor chains are increasingly used in automotive industry for controlling the valve opening mechanism of internal combustion engines. As the internal combustion engines experience frequent load-cycle changes and have only very restricted access for maintenance/ replacement of the chain; the situation demands wear resistant chain components. Conventionally, to achieve wear resistance and to avoid elongation caused by wear, the pins and/or bushings of the link chains are subjected to heat treatment like hardening and tempering; carbonization, carbiding etc. In spite of these treatments wear problems arise, particularly in the use as timing chains in an internal combustion engine. This reduces the engine’s reliability and necessitates an expensive exchange of the chain.
(b) In metal cutting, different wear processes exists like abrasive wear, crater wear, chemical interaction between the cut chip and the tool surface, abrasion by the outer edge of the chip. These deteriorative losses increases the tool cost and decreases the lifetime of tools.
An alternative method to reduce wear is to develop super hard coating by PVD method.