Optimization of the Laser Hardening Process by Adapting the Intensity Distribution to Generate a Top-hat Temperature Distribution Using Freeform Optics

Abstract

Laser hardening is a surface hardening process which enables high quality results due to the controllability of the energy input. The hardened area is determined by the heat distribution caused by the intensity profile of the laser beam. However, commonly used top-hat laser beams do not provide an ideal temperature profile. Therefore, in this paper the beam profile, and thus the temperature profile, is optimized using freeform optics. The intensity distribution is modified to generate a top-hat temperature profile on the surface. The results of laser hardening with the optimized distribution are thereupon compared with results using a top-hat intensity distribution.

Process Optimization of Wire-Based Laser Metal Deposition of Titanium

“…Therefore, to generate process maps identifying the melt pool characteristic as a function of the feed rate, the laser power, and the intensity distribution, a semi-analytical approach was used. The simulation was based on the superposition of moving point sources as it was described in previous publications [34]. The mathematical description can be seen in formulas 1 and 2…”

Effect of Tip Shape of Frictional Stir Burnishing Tool on Processed Layer’s Hardness, Residual Stress and Surface Roughness

“…High strength and abrasion resistance can be given by the induction hardening; the surface is hardened while the toughness in the core is maintained. Laser hardening process [6,7] is also employed to make high quality hardened layer on the limited area of the workpiece. These methods are used for auto parts and various kinds of mechanical parts.…”

“…However, the tensile residual stress often induced within the surface layer after machining and the tensile residual stress weakens the fatigue strength [10]. Therefore, shot peening is often applied after cutting in order to induce the compressive residual stress and higher hardness within the surface layer [6,7]. However, since the shot peening process is an additional process after the machining process, some kinds of combined process with the cutting process is requested from industry to improve the productivity.…”

“…process after the machining process, some kinds of combined process with the cutting process is requested from industry to improve the productivity. One solution is a laser hardening process [6,7], as mentioned before. Laser head can be mounted on the machine tools such as a lathe, then the laser hardening can be executed just after the turning on the lathe.…”

Surface hardening and finishing of metallic products by hybrid laser­ultrasonic treatment

“…It should be noted that the laser surface hardening technology allows treating complex shaped parts with minimal zones of thermal influence in comparison with traditional processes (induction, flame and bulk hardening) [1][2][3]. Currently, laser surface hardening is successfully used to improve the wear resistance of responsible parts [4]. It is known that the combined method of surface-plastic deformation (SPD) is carried out after laser heat treatment (LHT) under a separate scheme at ambient temperature.…”