Ulyanovsk State Technical University

About: Ulyanovsk State Technical University is a education organization based out in Ulyanovsk, Russia. It is known for research contribution in the topics: Computer science & Software. The organization has 600 authors who have published 658 publications receiving 2253 citations. The organization is also known as: Ulyanovsk Polytech University.

Effect of adhesion and the wear-resistant layer thickness ratio on mechanical and performance properties of ZrN - (Zr,Al,Si)N coatings

Abstract: The study involved the investigation of the effect of the thickness of the adhesion layers (0.3 and 0.7 μm) and the wear-resistant layer (2.0, 4.0, 6.0, and 8.0 μm) on the microhardness, adhesion bond strength, and performance properties of the ZrN-(Zr,Al,Si)N coatings. The scratch-test method was applied to study the adhesion bond strength to the substrate and coating failure patterns. The study revealed an effect of the coefficient kwa, determining the effect of the thicknesses of the wear-resistant and adhesion layers of the coating on the value of the critical load LC2. The study investigated the wear patterns and mechanisms for the specified coatings and the tool life of tools with these coatings in turning. An effect of the coefficient kwa which is the adhesion and wear-resistant layer thickness ratio on the tool life and a difference in the wear pattern dynamics for tools with these coatings with wear-resistant layers of equal thickness and adhesion layers of different thicknesses was revealed. The study also determined the chemical and phase composition of the coatings.

Improving the Efficiency of the Cutting Tool Made of Ceramic when Machining Hardened Steel by Applying Nano-Dispersed Multi-Layered Coatings

Abstract: The functional role of nano-dispersed multi-layered composite coatings (NMCC) deposited on the working surfaces of cutting inserts (CI) made of the layered high-strength ceramic (LHC) to equip the cutting tools when cutting hardened (high-strength) steels was investigated. It is shown that the variation in the composition, structure and properties of coatings allows controlling the contact processes at cutting, increasing the length of contact, reducing normal contact stresses and probability of micro- and macro-brittle failure of tool cutting edge. The mathematical models of cutting which establish dependences of flank wear land of the tool, the tangential component of cutting force, power of cutting and roughness of the machined surface from conditions of cutting of high-strengthen steels are developed. It is found out that the application of nano-dispersed ceramic multi-layered coatings on ceramic tool significantly increases its wear resistance and improves the quality of machining.

Investigation of the influence of the thickness of nanolayers in wear-resistant layers of Ti-TiN-(Ti,Cr,Al)N coating on destruction in the cutting and wear of carbide cutting tools

Abstract: The paper presents the results of the investigation into the formation of the nanolayer structure of the Ti-TiN-(Ti,Cr,Al)N coating and its influence on the thickness of coatings, their resistance to fracture in scratch testing, and the wear resistance of coated tools in turning 1045 steel. The structure of the coatings with the nanolayer thicknesses of 302, 160, 70, 53, 38, 24, 16, and 10 nm was studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution (HR) TEM. It is shown that the grain sizes in the nanolayers decrease to certain values with an increase in the thickness of the nanolayers, and then, with a further decrease in the nanolayer thickness, the grain sizes of the nanolayer grow as the interlayer interfaces cease to produce a restraining effect on the growth of the grains. The study found that the nanolayer thickness influenced the wear of carbide cutting tools and the pattern of fracture for the Ti-TiN-(Ti,Cr,Al)N coatings.