Nanostructured Multilayer Composite Coatings for Cutting Tools

The chapter deals with the specific features concerning the application of wear-resistant coatings to improve the performance properties of ceramic cutting tools. The paper discusses the theoretical background associated with the specific operation conditions and wear of ceramic cutting tools and influencing the choice of the compositions and structures of wear-resistant coatings. The studies were focused on the application of the Ti-(Ti,Al)N-(Zr,Nb,Ti,Al)N multilayer composite coating with a nanostructured wear-resistant layer, as well as the (Cr,Al,Si)N–(DLC–Si)–DLC–(DLC–Si) and (Cr,Al,Si)N–DLC composite coatings in order to improve the cutting properties of ceramic tools. The chapter presents the results of the comparative cutting tests for the tools with the coatings under study, uncoated tools, and tools with the Ti-(Ti,Al)N commercial coating. The wear mechanisms typical for ceramic cutting tools with coatings of various compositions have been investigated

Influence of Surface Layer Condition of Al2O3+TiC Ceramic Inserts on Quality of Deposited Coatings and Reliability during Hardened Steel Milling

The specific features of the destruction of tool ceramics, associated with structural heterogeneity and defects formed during diamond grinding, largely determine their reduced reliability (dispersion of resistance). This is most pronounced at increased heat and power loads on the contact surfaces and limits the industrial application of ceramic cutting tools. The surface layer of industrially produced Al2O3+TiC cutting inserts contains numerous defects, such as deep grooves and torn grains. During the milling of hardened steels of the 100CrMn type with increased cutting parameters, the “wear–cutting time” curves have a fan-shaped character with different wear rates. The resistance of the tool that was taken from one batch before reaching the accepted failure criterion has a significant variation in values (VarT is 30%). The study is aimed to evaluate the influence of the condition of the surface layer of Al2O3+TiC inserts processed by various types of abrasive treatments, such as diamond grinding, lapping and polishing, on the quality of the (TiAl)N and (TiZr)N coatings and the reliability of prefabricated end mills. The obtained “wear–cutting time” curves are characterized as closely intertwined bundles. The coefficient of resistance variation (the tool’s reliability) decreases by more than two times (14%). This can be used further in coating development to improve the performance of CCT

RETRACTED: Cutting ceramic inserts: the influence of abrasive machining and surface coatings on the operational characteristics

At the request of the Authors, the following article has been retracted: It has come to the attention of the journal and EDP Sciences that a similar version of the article has been previously published in another journal. The Editorial Board of Mechanics & Industry and EDP Sciences have agreed to retract the article (please see ‘Policies for publication of errata and for article retraction at http://www.mechanics-industry.org/about-the-journal/ethical-standard

RETRACTED: Cutting ceramic inserts: the influence of abrasive machining and surface coatings on the operational characteristics

At the request of the Authors, the following article has been retracted: It has come to the attention of the journal and EDP Sciences that a similar version of the article has been previously published in another journal. The Editorial Board of Mechanics & Industry and EDP Sciences have agreed to retract the article (please see ‘Policies for publication of errata and for article retraction at http://www.mechanics-industry.org/about-the-journal/ethical-standard

Retraction notice to: “Cutting ceramic inserts: the influence of abrasive machining and surface coatings on the operational characteristics”

At the request of the Authors, the following article has been retracted: It has come to the attention of the journal and EDP Sciences that a similar version of the article has been previously published in another journal. The Editorial Board of Mechanics & Industry and EDP Sciences have agreed to retract the article (please see ‘Policies for publication of errata and for article retraction at http://www.mechanics-industry.org/about-the-journal/ethical-standard

Study of the Influence of Silicon-Containing Diamond-like Carbon Coatings on the Wear Resistance of SiAlON Tool Ceramics

DLC coatings have low adhesive bond strength with the substrate and a high level of residual stresses. This paper is devoted to researching a complex of characteristics of a DLC-Si coating deposited on samples of SiAlON ceramics with intermediate coatings (CrAlSi)N pre-formed to improve the adhesive bond strength employing vacuum-plasma spraying. DLC-Si coatings were formed by chemical vapor deposition in a gas mixture of acetylene, argon, and tetramethylsilane supplied through a multichannel gas purge system controlling the tetramethylsilane volume by 1, 4, 7, and 10%. The SiAlON samples with deposited (CrAlSi)N/DLC-Si coatings with different silicon content in the DLC layer were subjected to XPS and EDX analyses. Tribological tests were carried out under conditions of high-temperature heating at 800C. The nanohardness and elasticity modulus of the rational (CrAlSi)N/DLC-Si coating with Si-content of 4.1% wt. were 26 ± 1.5 GPa and 238 ± 6 GPa, correspondingly. The rational composition of (CrAlSi)N/DLC-Si coating was deposited on cutters made of SiAlON ceramics and tested in high-speed machining of aircraft nickel-chromium alloy compared to uncoated and DLC-coated samples. The average operating time (wear resistance) of (CrAlSi)N/DLC-Si(4.1% wt.)-coated end mills before reaching the accepted failure criterion was 15.5 min when it was 10.5 min for the original cutters

Comprehensive analysis of internal and surface defects of ceramics

System approach to studying of causes of infringement of operational characteristics tool ceramic materials on the basis of complex researches and systematization of their volume and superficial defects is presented in article. The main directions of improvement of tool ceramics are allocate

Comprehensive analysis of internal and surface defects of ceramics

System approach to studying of causes of infringement of operational characteristics tool ceramic materials on the basis of complex researches and systematization of their volume and superficial defects is presented in article. The main directions of improvement of tool ceramics are allocate

Modeling of Thermophysical Phenomena When Cutting with Coated Tools

The results of computer simulation of thermophysical phenomena in the contact zone during blade cutting of metals with multi-layer composite wear-resistant coatings that ensure the adaptability of the cutting wedge to friction conditions are presented. On-site experimental studies of the cutting temperature during turning with various coatings, structural-phase analysis of the surface layer of the cutting tool to explain the mechanism of formation of secondary structures with a shielding effect – the effect of selforganization

Influence of aluminium and molybdenum on properties of coatings and cutting properties of coated tools

The paper presents the results of the investigation focused on the properties of the Cr,Mo-(Cr,Mo)N-(Cr,Mo,Al)N multilayered composite wear-resistant coating with a nanostructured wear-resistant layer. The nanostructure of the coating was investigated using transmission electron microscopy (TEM), the microhardness was measured, and the chemical composition was found. The cutting properties of a tool with the Cr,Mo-(Cr,Mo)N-(Cr,Mo,Al)N coating were studied during the turning of 09G2S silicon-manganese steel. It has been found that the use of a cutting tool with the Cr,Mo-(Cr,Mo)N-(Cr,Mo,Al)N coating reduces the flank wear rate by 1.65 times compared to an uncoated tool