Erween Abd Rahim

By Erween Rahim, Norazlan Warap and Zazuli Mohid

Nickel-based alloy can be found in different industrial applications especially in aircraft engines and hot end components of various types of gas turbines with its high strength, strong corrosion resistance and excellent thermal fatigue properties and thermal stability compared to conventional materials. However, nickel-based alloy is one of the extremely difficult-to-cut materials. During the machining process, the interaction between the tool and the workpiece causes severe plastic deformation and intense friction at the tool-workpiece interface. Because of the increasing demands in industries, any improvement of conventional machining processes or any other deployment of additional technique is directly related to higher productivity. Thermal-assisted machining (TAM) has become an effective alternative to the conventional machining of these difficult-to-cut materials. Various types of heating methods and the beneficial effects on machining of nickel-based alloys are discussed in this chapter. Finally, TAM was proven as an efficient technique to increase the machinability of nickel-based alloys in terms of tool life, surface roughness and cutting force.

Part of the book: Superalloys

By Erween Abd. Rahim, Amiril Sahab Abdul Sani and Norfazillah Talib

Metalworking fluids were applied during the machining process to lubricate and cool the machine tool in order to reduce wear, friction, and heat generated. The increasing attention to the environment and health impacts leads to the formulation of eco-friendly metalworking fluids derived from vegetable oils (Jatropha and palm oils) to substitute the use of mineral-based oil. The present work focuses on the performance of refined bio-based metalworking fluids during tapping torque and orthogonal cutting processes. Bio-based metalworking fluids were formulated using 0.05 wt.% of hexagonal boron nitride (hBN) and 1 wt.% of phosphonium-based ionic liquid [P66614][(iC8)2PO2] in a modified Jatropha and palm olein oils and were examined for their rheological properties in comparison with a commercially obtained synthetic ester (SE)-based cutting fluid. The tapping torque performance of the refined bio-based metalworking fluids was evaluated for their torque and efficiency. In addition, the performance of these bio-based metalworking fluids on orthogonal cutting parameters such as cutting force, cutting temperature, chip thickness, tool-chip contact length, and specific cutting energy was highlighted. The results obtained revealed that the rheological properties of the newly formulated bio-based metalworking fluids were improved. From the tapping torque and orthogonal cutting performances, it was proven that the modified palm and Jatropha oils possess good anti-wear and anti-friction behavior compared to SE. In conclusion, the newly formulated bio-based metalworking fluids are suitable for the use as a new advanced renewable metalworking fluid for machining processes that correspond to the energy-saving benefits and environmental concerns.

Part of the book: Tribology, Lubricants and Additives