Plasma-Beam Processing of Tools Made of SiAlON Dielectric Ceramics to Increase Wear Resistance When Cutting Nickel–Chromium Alloys

Abstract

This research aimed at an increase in wear resistance of round cutting plates manufactured with SiAlON dielectric ceramics through deposition of wear-resistant coatings. To increase effectiveness of the coatings, their adhesion was improved by the removal of defective surface layers from the cutting plates before the deposition. As the depth of caverns and grooves appearing on the cutting plates due to manufacturing by diamond grinding reached 5 µm, a concentrated beam of fast argon atoms was used for the removal of defective layers with a thickness exceeding the depth of caverns and grooves. At the equal angles of incidence to the front and back surfaces of the cutting wedge amounting to 45 degrees, two-hour-long etching of rotating cutting plates provided removal of defective layers with thickness of ~10 µm from the surfaces. After the removal, the cutting edge radius of the plates diminished from 20 to 10 µm, which indicates the cutting plates’ sharpening. Wear-resistant TiAlN coatings deposited after the etching significantly improve the processing stability and increase wear resistance of the cutting plates by not less than 1.7 times.

Technological principles for removal of defective surface layer on grinded ceramic products by etching with accelerated argon

“…The developed technological approach for removing a defective surface layer from ceramic samples can be classified as a kind of "dry" etching technology [17]. The removal is carried out due to its physical spraying with high-energy particles of inert gases that do not enter into a chemical reaction with the substrate material.…”

The Influence of Surface Texturing of Ceramic and Superhard Cutting Tools on the Machining Process—A Review

“…Several materials such as silicon carbide (SiC), titanium carbide (TiC), and titanium nitride (TiN), are added into the Al 2 O 3 or Si 3 N 4 matrix in order to improve the mechanical properties of the ceramic cutting tools. Si 3 N 4 -based ceramics are used in cutting tools called SIALON that came into use during the 1980s and have superior characteristics to Al 2 O 3 -based ceramics when some factors are considered [ 67 , 68 ]. For instance, the flexural strength of Si 3 N 4 can be in the range of 700–1100 MPa.…”

Granulation of Silicon Nitride Powders by Spray Drying: A Review

“…Oxides of rare earth, such as Y 2 O 3 , Yb 2 O 3, and Sc 2 O 3 , as well as metal oxides-MgO or Al 2 O 3 , are frequently used as sintering aids for silicon nitride [ 33 , 34 , 35 , 36 ]. Besides, MgO, Al 2 O 3 , and Y 2 O 3 are used to form phases such as SiAlON, MgSiO 4 , and MgSiO 3 [ 37 , 38 ]. In addition to the listed materials, other additives such as MgSiN 2 , YbF 3 , and Y 2 Si 4 N 6 C have been proposed to increase the nitrogen/oxygen ratio [ 33 , 39 ].…”