In times of societal development, sustainability has become a major concern for many manufacturers in the metal industries. In this context, surface texturing of cutting tools offers a promising approach in terms of reducing energy consumption and material waste. In this work, direct laser interference patterning is utilized for producing periodic line-like structures with spatial periods of 2.0 µm and 5.5 µm on rake-flank faces of cemented tungsten carbide cutting inserts. Structure depths up to 1.75 µm are reached by controlling the applied number of laser pulses. Turning experiments under lubricated conditions carried out on Al 6061 T6 parts with textured and untreated tools are performed to determine their tribological performances. The used textured cutting tools can effectively decrease machining forces up to 17% due to the corresponding improvement in frictional behavior at the tool/chip interface. Furthermore, the laser-processed tools produce thinner chips and decrease the surface roughness by 31% of the aluminum work piece.

No abstract

Nowadays, improving processes sustainability has become a major topic for many manufacturers in metal processing industries. Next to the challenging rise of costs of raw material and tools, innovative and hard to process materials enter the market. Here, surface functionalization of cutting tools is devised as a convenient approach for reducing energy consumption as well as material losses. In this work, direct laser interference patterning (DLIP) is used for manufacturing periodic line-like structures with spatial periods of 5.5 µm on tungsten carbide. The texturing is applied on rake-flank faces of the cutting inserts, leading to texture depths up to 1.75 µm by controlling the amount of used laser pulses. Moreover, turning experiments under lubricated conditions carried out on Al 6061 T6 parts with structured and untreated tools are performed to investigate the tribological performance. In result, the used DLIP-functionalized cutting tools could effectively decrease machining forces up to 12 %. This is caused by the corresponding improvement in frictional and improved lubrication behavior at the tool/chip interface. Furthermore, the laser-processed tools generate thinner chips, which leads to a decrease in surface roughness by 31 % of the aluminum work piece. This work thus offers insight into the viability of improving cutting tools by laser surface micro patterning for upcoming innovative materials designed for improving tool wear resistance, energy efficiency and surface quality.

Laser chemical machining (LCM) is intentionally limited in its removal rate to avoid disturbing boiling bubbles in the process fluid. To overcome this limitation, an enhanced material removal model is required based on surface geometry and temperature in-process data. For this purpose, fluorescence measurements and confocal microscopy are combined to enable in-process experiments in LCM environment. Derived from fluorescence effects, the geometry and surface temperature are indirectly determined under LCM-equivalent conditions such as thick fluid layers and gas bubbles in the beam path.

Improving processes sustainability to address upcoming demands in metal processing industries such as innovative and hard to process materials has become a major topic for many manufacturers. Therefore, new tool material compositions or surface coatings are continuously developed. In this context, surface functionalization of cutting tools is foreseen as a convenient approach for minimizing material losses and thus energy consumption. In this work, laser induced periodic surface structures (LIPSS) are used for manufacturing quasi-periodic line-like patterns on tungsten carbide inserts. The textured tool surfaces show low spatial frequency LIPSS (LSFL) with spatial periods of 500 nm to 600 nm as well as high spatial frequency LIPSS (HSFL) with a spatial period of ~100 nm. Furthermore, the texturing is applied on rake and flank faces of the cutting tools with different offsets to the edge between 0 and 0.2 mm. The wettability analysis reveals a decrease of static contact angles for the used cutting fluid (CIMSTAR) from 38° to 12°, suggesting an improved cooling process during the machining step. In addition, turning experiments under lubricated conditions are carried out on Al 6061 T6 parts to investigate the tribological performance. The used LIPSS-functionalized cutting tools could effectively decrease the main machining forces by 10 %, the feed force by 21 % and the passive force by 9 %. Furthermore, the laserprocessed tools generate thinner chips, which leads to a decrease in surface roughness by 31 % of the aluminum work piece.