Machinability of high strength molybdenum-refined graphite grey cast iron and conventional vermicular automobile engine heads using heptagonal and double-sided carbide inserts

Abstract

In the current scenario, industry has been faced with growing restrictions imposed by law, aimed at reducing the emission of fuel gases and pollutants into the atmosphere. The automotive industry is seeking to produce vehicles with higher performance to match these needs, so that engines become increasingly smaller, less pollutant and silent. Regulatory factors have guided and contributed to the development of new technologies applied to the internal combustion engine. Depending on such developments, maximum injection and combustion pressures can be achieved, thus, ensuring more efficiency and better performance, in addition to emission reduction. However, recent technology requires engines to withstand even greater mechanical stresses, which can inevitably lead to a component premature failure if no additional improvement are made. Therefore, there has been an incessant search for an alloy capable of replacing conventional gray cast iron, commonly used in the manufacture of blocks, but not yet suitable for high pressures. This work objective is to evaluate the face milling cutting power behavior in FC300 high strength cast iron with the addition of molybdenum and refined graphite, grade (FC300Mo + RG), for application in engine heads, compared to alloys already used for this purpose, such as the FC250 gray cast iron, the FC300 molybdenum alloyed gray cast iron, grade (FC300Mo), and the FV450 vermicular cast iron, grade (CGI).