Influence of the surface layer characteristics on the regularities of the cutting process

Abstract

Abstract. The article considers the influence of the surface layer characteristics on the regularities of the cutting process and the formation of the quality of the surface machined. This effect has been confirmed by the study results of the combined cutting method with advanced plastic deformation (APD). The work estimates the impact of the change in the surface layer properties on the forces and temperature of cutting, stability of the chip formation and quality parameters of the surface machined. The rise in the tech level specifies the challenges of increasing the effectiveness of the parts production and formation of the required performance characteristics of their surfaces. It is noteworthy that at present, inadequate attention is paid to all the parameters of the machine part surface both in construction, process design, and production. Machining considers for the most part the geometrical parameters and surface roughness. To improve the surface performance parameters such as the surface structure, hardness, wear resistance, etc., some special operations are assigned, including the strengthening treatment, honing finishing operations and heat treatment of various types. However, in certain cases, the desired surface parameters can be achieved by less number of operations and at less cost.Besides, the concept of machining design, in our view, requires some updating and improvements. Despite the continuing technological advance and potential of certain branches of machine-building industry, which are the basis for any industrial production (first of all, machine tool building, metallurgy, cutting tool production, etc.), for upward movement, they cannot fully ensure the necessary stability of all technological system parameters in course of machining operations. So, this fact causes the parameter instability of the surface machined, and hence the performance instability of the manufactured parts, assemblies, mechanisms, and machines.The machining procedure of a part can be considered as a sequence of operations on a workpiece. Each operation to some extent changes a set of the surface parameters of the workpiece machined, with the processing result to depend not only on the type and mode of exposure and the tool applied, but also on the previous state and the surface layer of the workpiece. The processing result depended not only on the type and modes of action and the tool applied, but also on the previous state of the workpiece and the surface layer. The effectiveness of the cutting process was considerably influenced by the properties of the material being processed, the workpiece and the cutting tool. The indicated properties given in the reference literature and certificates for tool and construction materials were averaged and allowed for a wide range of characteristics [1,2]. This significantly reduced the reliability and effectiveness of the technological preparation of production and also affected the stability of the processing results.For a better understanding the essence of this issue, let's l...

Determination of Optimal Hardfacing Modes for Recovering Electric Motor Shafts

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“…The restored shafts are subject to further machining to ensure the geometric dimensions, the surfacesꞌ relative posi the roughness. Since the deposited layer has a high hardness due to the presence of high-hardness carbides and a viscous metal base [25], this causes difficulty in milling and grinding [25,26], high tool consumption [27], and in connection with this, the hardness parameter of the deposited layer considered as the main one.…”

Investigation of the Performance Properties of Parts Surfaces to Be Recovered by SemiAutomatic Hardfacing

“…It is known that deposited coatings have high technological properties, can provide the specified requirements for operational properties [7], due to the correct choice of electrodes, welding wires and powders for wear-resistant surfacing, appropriate grades, alloying fluxes, thermal and other types of treatments after surfacing [8].…”

Formation of the Surface Layer Properties in Edge Cutting Machining of Stainless and Heat-Resistant Steels

“…This was expressed in reduction of the oscillation amplitude of the shear angle β (Figure 3), which characterized the stabilization of the cutting process. Thus, improving the machinability of stainless and heat-resistant steels, with the surface layer characteristics of the workpiece processed under the influence of the APD to be changed, consists in reducing the cutting forces and temperature, general decrease in instability of the chip-forming process and, as a consequence, improving resistance of the cutting tool and surface roughness [4,5].…”