Multilayer composite nanoscale coatings as a method to increase reliability and tool life of cutting tools made of mixed ceramic Al₂O₃-TiC

Abstract

-The paper studies the challenges of improvement of reliability and tool life of ceramic cutting tools made of mixed ceramic Al2O3-TiC through application of nanoscale multilayer composite coatings, deposited through the method of filtered vacuum arc deposition. The paper studied wear mechanisms of ceramic cutting tools with and without coatings, as well as reliability of ceramic tools. It is found out that coatings reduce the wear rate of a ceramic tool along its flank face. The difference between flank wear land VB for an uncoated ceramic tool and a ceramic tool with coating reaches up to 60 µm during cutting time of 10-12 min, with the better results on reduction of the wear rate of flank wear land shown by ceramic cutting inserts with nanoscale multilayer coating Ti-(TiAl)N-(TiCrAl)N as compared with coating Ti-(TiAl)N-(ZrNbTiAl)N. The tests showed that failures of uncoated ceramic tools follow the exponential distribution law, and the coefficient of failure variation of such tool is 1.08. Meanwhile, the failures of coated ceramic tools follow the law of Weibull distribution, and the coefficients of failure variation are 0.39-0.45, respectively. Thus, it is found out that the deposition of multilayer composite coatings of recommended composition on working surfaces of a tool equipped with cutting inserts of mixed ceramic Al2O3-TiC provides the increased operating reliability of the ceramic tool and predicts its failures.

The Effect of TiC Additive on Mechanical and Electrical Properties of Al2O3 Ceramic

“…The TiC content in the samples makes them conductive since the electrical resistance of titanium carbide is 6.0 × 10 −7 Ω•m [21,22,64], which is higher than the value for the brass wire ( Table 2). As the equivalent ratio of TiC content in the samples increases, the conductivity of the samples also increases with no loss of mechanical properties.…”

“…In addition, the widespread use of these materials requires a non-traditional way of manufacturing [19][20][21][22]. Today, materials are usually machined by grinding using abrasive materials or hard tools.…”

Identification of Technological Parameters of Ni-Alloys When Machining by Monolithic Ceramic Milling Tool

“…Mechanical properties of this material is summarized in the table 1. [7,14] As we can see in the table 1, used improved ceramics has higher flexural and compressive stress than the ordinary ceramics but lower hardness. Mainly this fact (or parameters) guarantees better mechanical properties of improved ceramics for machining of hard-to-machines materials.…”

“…Selection of suitable type of cutting material is an important factor in designing of cutting tools. The most important properties of cutting material include sufficient hardness and wear resistance, also in high temperatures and resistance to physical and chemical effects [7,14] For machining of hard-to-machine materials, there is recommended following materials with suitable properties such as sintered carbides; cermet; cutting ceramics; synthetic and very hard polycrystalline materials.…”

Increased Operating Properties of Cutting Ceramics by Application of Nanostructured Multilayer Wear-Resistant Coating

“…An effective method to improve physical and mechanical properties of cutting ceramic is the deposition of functional coatings on the working surfaces [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. This allows control of the contact processes to improve the wear resistance and the thermomechanical strain response of the cutting edges.…”