A Novel Experimental Test Bench to Investigate the Effects of Cutting Fluids on the Frictional Conditions in Metal Cutting

Abstract

The tribological effect of cutting fluids in the machining processes to reduce the friction in the cutting zone is still widely unknown. Most test benches and procedures do not represent the contact conditions of machining processes adequately, especially for interrupted contacts. This results in a lack of knowledge of the tribological behavior in machining processes. To close this knowledge gap, a novel experimental test bench to investigate the effects of cutting fluids on the frictional conditions in metal cutting under high-pressure cutting fluid supply was developed and utilized within this work. The results show that there is a difference between the frictional forces in interrupted contact compared to continuous contact. Furthermore, the cutting fluid parameters of supply pressure, volumetric flow rate, and impact point of the cutting fluid jet influence the frictional forces, the intensities of which depend on the workpiece material. In conclusion, the novel test bench allows examining the frictional behavior in interrupted cuts with an unprecedented precision, which contributes to a knowledge-based design of the cutting fluid supply for cutting tools.

Evaluating the Tribological Behaviour in Cutting Operations Using a Modified Ball-on-Disc Open Tribotester

“…This choice was influenced by its extensive use in highly stressed components, such as crankshafts in critical industrial applications. This type of steel possesses outstanding mechanical properties in terms of high strength (≥1000 MPa) and toughness [28]. As for the balls, they were produced from tungsten carbide with 6% cobalt (Co).…”

“…Furthermore, Lakner et al [28] shifted their focus to the influence of plastic deformation and subsequent thermal softening as key factors in diminishing the coefficient of friction (COF). The research conducted a thorough comparative analysis of frictional behaviour, examining two distinct workpiece materials, Ti-6Al-4V and 42CrMo4 + QT, in conjunction with a cemented carbide tool coated with TiCN.…”

Influence of metal working fluid on chip formation and mechanical loads in orthogonal cutting

“…These results were later validated for different oil types [8] and were also confirmed in [9] with an uncoated pin. Lakner and Hardt used a defined contact between the flank face of a TiCN-coated cemented carbide tool and an AISI4140 shaft to identify the friction coefficient [10]. They determined friction coefficients µ = 0.2-0.3 for dry and wet processes and sliding velocities v s = 40-120 m/min.…”