A study on rock cutting forces and wear mechanisms of coated picks by lab-scale linear cutting machine

Abstract

Conical cemented carbide tip has facilitated extensive application in the field of mining engineering because of their exceptional combination of strength, hardness and high wear resistance. This paper focuses on different cutting forces and wear mechanisms in a conical pick which has been used in a surface miner machine for rock cutting. In the present work, an attempt has been made by coating aluminium titanium nitride (AlTiN) on the tip to calculate the cutting forces and to understand the wear mechanisms. Modified shaper machine was used to cut the rock sample linearly and their corresponding forces were measured by using a 3D strain gauge octagonal dynamometer. Coated tool possess highest hardness of 22.47 GPa with lowest wear rate of 2.54 10−4 cm3 /cm and 4.42 10−4 cm3 /cm, whereas uncoated tool with lowest hardness of 19.10 GPa depicts wear rate of 2.95 10−4 cm3/cm and 5.65 10−4 cm3/cm for 2 mm and 4 mm depths of cut. Parameters such as cutting forces, amount of coal removed, cutting efficiency and specific energy generated during cutting were also analysed for different depths of cut and the best compromise was found among them. The worn out surface has been critically examined using scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. This study may be helpful for the selection of suitable surface miner machine and their cutting pick for hard rock cutting operation in mines.