Ytterbium impulse laser for surface modification of tool steel with B₄C-Al powders

Abstract

The paper deals with a new application solution of Ytterbium Picosecond Pulsed Fiber Laser for surface modification of 3Kh2V8F hot-work tool steel (the analog of AISI H21 steel). Surface modification was conducted by B4C-Al powders from preplaced pastes followed by laser heating. The ratio of B4C-Al powders was taken as 5/1 by weight and the paste thickness was approximately 1 mm. Laser treatment was conducted according to the following parameters: 1070 nm of wavelength, 100 W of power, 1 mJ of pulse energy, 100 ns pulse duration, pulse frequency range from 50 kHz to 90 kHz. Several tracks with different widths were obtained as a result of treatment depending on velocity of the laser move. EDS analysis showed that B4C particles were not completely dissolved in the weld beads. However, an enhanced concentration of boron (8-12 wt.%) was revealed in the vicinity of B4C particles. The aluminum concentration was low (up to 0.79 wt.%) on the surface of the weld beads.

Surface Alloying of Tool Steels with Ytterbium Pulse Fiber Laser

“…Processing parameters for laser surface modification were taken as radiation wavelength of 1070 nm, 50-90 W of output power, 1 mJ of radiation pulse energy, 100 ns of pulse duration and pulse frequency range from 50 kHz to 90 kHz. Two laser positions (higher and lower) and two treatment periods (4 minutes and 10-20 sec) modes were tested [3].…”

“…As a result, alloying materials are dispersed in the form of particles in the molten bath (Fig. 1) [3]. Laser cladding is one of the most promising methods for applying hardening coatings.…”