Fracture Toughness and Tribological Wear Behaviour of Micro Alloyed Pearlitic- Ferritic Ductile Cast Iron

Abstract

Fracture toughness and wear behaviour of micro alloyed ductile iron were investigated. Hardness, fracture, fracture toughness and wear tests were carried out on the ductile irons samples (D1, D2, D3, D4 and D5), containing micro alloyed nickel, molybdenum, copper and chromium in an amount of 0.2 % or less. They were characterized using optical metallurgical microscope and they contained pearlitic-ferritic matrix structure. They were subjected to wear test at room temperature based on pin-on-disk operation. Fracture surfaces and the wear track were studied using scanning electron microscope and found that the fracture surfaces majorly consist of fibrous with little cleavage fracture pattern in some samples. Wear mechanism is delamination with adhesive wear behavior. The specific wear rate was found to decrease with increasing hardness of the material and coefficient of friction of the ductile irons during test.

MECHANICAL DAMPING CHARACTERISTICS OF DUCTILE AND GREY IRONS MICRO-ALLOYED WITH COMBINATIONS OF Mo, Ni, Cu AND Cr

“…Similar outcome was achieved with the use of manganese, nickel, molybdenum, and copper as micro alloying addition, as long as the composition of these elements did not exceed 0.5% [9]. It has been reported that optimal selection of combinations of Mo, Cr, Ni and Cu as micro alloying addition in ductile irons, results in improved strength, toughness and wear resistance [10,11]. However, the effect of these micro alloying additions on the damping properties of ductile irons has not come under scrutiny.…”

“…The procedures adopted for the production of the ductile irons have been reported in details by Omole et al [10,11]. The process summarily, involved utilization of grey cast iron scrap as base metal, while ferro-molybdenum (72%), ferro-chrome (64% Cr), copper and nickel, were utilized as micro alloying additions.…”