Graphite Flake Size Effects to Thermal Durability of Automobile Flywheel Under Forced Slippage

Abstract

-The objective of this study is to investigate thermal durability of grey cast iron GJL250 material flywheel based on casting graphite flake size under abusive and unusual driving condition which causes forced slippage. In daily routine, drivers may make half press of clutch pedal and switch the gear out of sequence during long traffic condition. This case leads to slippage between flywheel and clutch that causes energy dissipation in clutch house. During slippage, thermal load on flywheel increases and when it reaches critical level this may cause thermal cracks on flywheel. In this study, graphite flake size effects on thermal durability were investigated. In order to simulate daily abusive usage, flywheels which have different graphite flake type and size were subjected to forced slippage test at the test bench which simulates the abusive usage on the car. The findings of this study is different size of graphite flake types on flywheel directly effects the thermal performance of material and may cause prominent cracks during over dissipated energy occurrence. At the end of the forced slippage test, the cast iron which has higher graphite size completed the test without crack, whereas prominent cracks were observed on the casting which has smaller laminar graphite size.

Roughing, semi-finishing and finishing of laser surface modified nickel bonded NbC and WC inserts for grey cast iron (GCI) face-milling

“…Grey cast iron (GCI) is a type of cast iron with graphite, which is typically used in applications where high stiffness is more important than tensile strength [16]. Grey cast iron has several attractive properties such as good wear resistance, corrosion resistance, vibration damping and thermal conductivity [16].…”

“…Grey cast iron (GCI) is a type of cast iron with graphite, which is typically used in applications where high stiffness is more important than tensile strength [16]. Grey cast iron has several attractive properties such as good wear resistance, corrosion resistance, vibration damping and thermal conductivity [16]. These properties and the high stiffness, allow GCI to have several automotive industry applications, including internal combustion engine cylinder blocks, flywheels and clutch plates [16].…”

“…Grey cast iron has several attractive properties such as good wear resistance, corrosion resistance, vibration damping and thermal conductivity [16]. These properties and the high stiffness, allow GCI to have several automotive industry applications, including internal combustion engine cylinder blocks, flywheels and clutch plates [16]. Grey cast iron engine blocks and cylinder heads are produced by casting, followed by semi-finishing and finishing machining processes to the final dimensions.…”