Author(s)

KRZYSZTOF JAMROZIAK, TETIANA ROIK

Abstract

This paper studies the effect of technological parameters to the manufacture of new effective antifriction composite materials based on 7HG2VМF tool steel grinding waste with CaF₂ additions as solid lubricants in structures, having mechanical and tribological properties for high temperature friction (bearings perform at a temperature of up to 550°С, a sliding speed of 1 m/s, and a pressure up to 5.0 MPa, in air). This paper illustrates the mechanism of structure formation of the new materials and its effect on properties after using developed technological modes. Such technology can ensure a micro-heterogeneous fine-grained structure. The composite structure consists of a matrix based on tool steel waste and the uniformly distributed CaF₂ solid lubricant. The metal matrix is pearlite and consists of an α-solid solution based on iron with hard grains of alloying elements of carbides. Such heterogeneous structure promotes a high level of antifriction properties under severe operating conditions. The behavior of CaF₂ in the friction area under high temperature operating conditions has been shown. The CaF₂ solid lubricant is evenly distributed over the entire friction surface. Calcium fluoride and chemical elements of the contact pair form an antifriction film, which provides self-lubricating conditions. The possibility of predicting and controlling the behavior of antifriction materials at a high temperature, by the selection of initial metal grinding waste, for ensuring the high level of functional properties, has been demonstrated. The use of grinding waste to produce effective antifriction materials makes it possible to partially solve the global problem of environmental protection.

Keywords

antifriction composite material, grinding waste, tool steel, solid lubricant, technology, structure, properties, friction films