Abstract
One of the promising directions of hardening of high-speed steel tool is the creation on their surface of the layered structures with the gradient of physic-chemical properties between the wear-resistant coatings to the base material. Among the methods of such surface modification, a special process takes place based on the use of pulsed high-intensity charged particle beams. The high speed of heating and cooling allows structural-phase transformations in the surface layer, which cannot be realized in a stationary mode. The treatment was conducted in a RITM-SP unit, which constitutes a combination of a source of low-energy high-current electron beams “RITM” and two magnetron spraying systems on a single vacuum chamber. The unit enables deposition of films on the surface of the desired product and subsequent liquid-phase mixing of materials of the film and the substrate by an intense pulse electron beam. The article discusses features of the structure of the subsurface layer of high-speed steel M2, modified by surface alloying of a low-energy high-current electron beam, and its effect on the wear resistance of the tool when dry cutting hard to machine Nickel alloy. A significant decrease of intensity of wear of high-speed steel with combined treatment happens due to the displacement of the zone of wear and decrease the radius of rounding of the cutting edge because of changes in conditions of interaction with the material being treated.
Highlights
Despite a year-by-year increasing usage of tools made of hard alloys, cutting ceramics and super hard materials, the quantity of high-speed steels used in the production of metal-machining tools is not decreasing at all [1,2]
The successful introduction of wear-resistant coatings is impeded by the fact that, due to a great difference in physical and mechanical properties of the substrate and the coating, there is often observed an accelerated deterioration of work surfaces of the tools during plastic deformation of the substrate under heavy loads [16,17,18]
This disadvantage may be dealt with by forming some transition layer which may be obtained, e.g., by performing a thermochemical treatment preceding the application of a wear-resistant coating; the ion nitriding process is used rather widely [19,20]
Summary
Despite a year-by-year increasing usage of tools made of hard alloys, cutting ceramics and super hard materials, the quantity of high-speed steels used in the production of metal-machining tools is not decreasing at all [1,2]. The successful introduction of wear-resistant coatings is impeded by the fact that, due to a great difference in physical and mechanical properties of the substrate and the coating, there is often observed an accelerated deterioration of work surfaces of the tools during plastic deformation of the substrate under heavy loads [16,17,18] This disadvantage may be dealt with by forming some transition layer which may be obtained, e.g., by performing a thermochemical treatment preceding the application of a wear-resistant coating; the ion nitriding process is used rather widely [19,20]. Some interesting compositions, which may be used to obtain modified surface layers by the method considered to increase the durability of tools made of relatively middle-alloyed high-speed M2 steel with average heat resistance, during longitudinal turning of heat-resistant nickel alloy NiCr20TiAl, are discussed
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have