Investigation of the thickness and microhardness of electrospark coatings of amorphous and nanocrystalline alloys

Abstract

The results of investigation of the thickness and microhardness of electrospark coatings (ESCs) of amorphous and nanocrystalline alloys (NCAs) are presented. It is shown that the application of amorphous and NCAs as electrode materials increases the thickness of ESCs and the produced coatings are characterized by high hardness.

Investigation of the Properties of Non-Tungsten Electro-Spark Coatings on High Speed Steel

“…The minimum and maximum values (borders) of the thickness δ, of surface roughness Ra, and microhardness HV of coatings, obtained from the studied electrodes at the different used values of parameters of regimens for LESD is shown in Table1. From the data presented in the table it seen that the roughness values Ra are significantly lower than those obtained with the vibrating apparatus [7,8], even with the use of nano-electrode materials [9], but the thickness  is also lower. Moreover, the higher the content of soldering materials in the composition of the layering electrode, the higher are the values of roughness Ra and the thickness δ of the obtained coatings and microhardness slightly decreases.…”

“…the presence of amorphous structures in the coatings is also lower. The comparison of the phase composition of the coatings obtained with the investigated electrodes indicates that the resulting with electrode TiC-TiN layers are richer in carbides, nitrides and carbonitrides, which also explains its higher single measured values of microhardness of the coatings obtained with the others electrodes.In the case of LESD with machines "Elfa", the obtained structure is analogous to the sublayer obtained by the vibration methods, but the latter often form defects and a relatively non-uniform thickness of the formed layer [5,8,9].…”

“…This ensures of LESD certain advantages that give him priority over the vibration methods for stratification of all tools and parts with high requirements on the quality of the work surface, for example, obtaining of thin, dense and smooth coatings on the cutting edges of tools and dies [3][4][5][6]. For the electrodes in the LESD mainly hard alloys based on WC-K10, K20, P10, P25 are used [5,[7][8][9], which in many cases limits the obtaining of the desired effect of the applied coatings. In this respect, the hard-alloy electrodes based of TiC, TiN, TiCN are also of interest.…”

Studying the effect of estimated parameters on the distribution of temperature zones in the elements of a mold under conditions of activated processing

“…Paper [10] reports the results of studying the heating of porous materials with electric current; however, the heat and electrophysical processes in the electrodes-punches are disregarded. In work [11], an equation for the temperature in metal between the electrodes was derived taking into consideration the heat transfer in the electrodes; however, no expression for the temperature field in electrodes is provided.…”

Study of the composition of innovative materials for the restoration and strengthening of machine parts

“…The material must have sufficient hardness, strength, and optimal thermal properties for the friction pair. Amorphous and nanocrystalline alloys often have such mutually exclusive properties [1][2][3][4][5]. With their help, it is possible to obtain strengthening coatings with amorphous or nanocrystalline structures that have high physical and mechanical properties and wear resistance [6][7][8].…”