THERMO-DEFORMATION LASER SINTERING OF DIAMOND-CONTAINING COMPOSITES FOR ABRASIVE MACHINING OF MACHINE-BUILDING PRODUCTS

Abstract

The main drawback of existing technologies for producing diamond-containing abrasive tools is their low efficiency
and the limited number of suitable binder materials for the working layer with filler. This is due to the maximum allowable
heating temperatures of diamonds (up to 700–800 °C). The prolonged sintering process, unpredictable tool durability, increased
diamond consumption, and high processing cost necessitate the development of new synthesis methods for composites with
superhard materials (SHM).
Therefore, this study explores a fundamentally new process of laser synthesis of diamond-containing composite
materials for the production of abrasive tools. These tools can be used for grinding large-size sheet products made of carbon
fiber, fiberglass, organoplastics, honeycomb panels, and other materials widely used in machine building.
Synthetic diamonds AS125 (grain size 425/300) were used as abrasive grains, while the binder consisted of Ni-based
powders (fraction 50 μm) with the addition of Co. Technological equipment equipped with a Maxphotonics 4th-generation fiber
laser emitter (λ = 1.06 μm) was employed, along with a set of experimental methods of physical materials science.
As a result of thermo-deformation laser sintering in an inert atmosphere (source power 500–1000 W, exposure time
0.18–0.36 s), a dense, defect-free diamond-containing layer was synthesized on the surface of a steel substrate.
The addition of Co to the Ni-based binder enabled the formation of an extensive contact area with the diamonds and
allowed for the analysis of the interfacial morphology between diamond and binder, depending on the irradiation conditions.
The optimal laser processing parameters were determined, which ensure the formation of Cr₇C₃ carbide and improved
wettability of the diamonds by the binder material.