IDEA #4E2Q9N Electrolytic Plasma Thermocycling Treatment (Eptt)

APPLIED RESEARCH • PLASMAPHYSICS AND TECHNOLOGY ELECTROLYTIC PLASMA THERMOCYCLING TREATMENT ((EPTT)) TECHNOLOGY AND EQUIPMENT Description EPTT is performed by means of electric discharges in the plas(cid:2) ma layer between the workpiece surface and electrolytic elec(cid:2) trode. The plasma material is a water(cid:2)based electrolyte. This electrolyte is used also for cooling of the heated surface. Treatment can be performed with several heaters at a time to raise the process productivity. Thermal(cid:2)cycling surface treatment is performed with the elec(cid:2) tric current commutated by electrolyte (aqueous solution of alkali). Alloying elements (metal ions) are added to the electrolyte and participate in the diffusion process of alloying of the heated surface of a part. Cooling of the surface is provided by the electrolyte and due to heat capacity of the part. Cycling of the heating and solidification processes enhances diffusion and provides formation of a microcrystalline struc(cid:2) ture in the surface layer. Innovative Aspect and Main Advantages We use ingenious electrolytic(cid:2)plasma devices (Fig. 1) operat(cid:2) ing on the basis of utilization of a liquid electrode, i.e. elec(cid:2) trolyte, formation of a plasma layer on the part surface and generation of energy in this layer in the form of electric dis(cid:2) charges. This provides thermal(cid:2)cycling heating, alloying and structuring of the surface of metal parts to a depth of 0.1(cid:2)10 mm. The technology is environmentally clean since EPTT process accompanied by emission of water vapors only. The power uti(cid:2) lization efficiency of 80(cid:2)90 % makes this technology power(cid:2) saving. The non(cid:2)contact temperature sensor and control system pro(cid:2) vide automation of the technology and thermal cycling of the surface of parts in a range of preset temperatures. Areas ooff Application This technology is efficient both for abrasive wear protection of the surface of parts and for producing of a hardening layer on parts of the type of hydraulic rods, deformation rollers and rolling mill rolls. The technology is effectively applied in mining engineering, metallurgy, agriculture and wood working industry. Main advantages of the technology are a multiple energy sav(cid:2) ing, improvement of physical(cid:2)operating properties of the work(cid:2) ing layer and, therefore, performance of metal parts operating under wear and complex stress conditions. Basic grounds for application of this technology are: High energy density in treatment zone and possibility to regu(cid:2) late it smoothly; Short(cid:2)time and locality of treatment limiting the zone of ther(cid:2) mal treatment; Simplicity of plasma jet generation and possibility to realize treatment of complex surfaces without contact; The possibility of automation of treatment process. 36 а) b) v) g) Fig. 1. Devices for hardening of cylindrical parts: a) mounted on part; b) for hardening saw, v) for hardening roller, g) device fixed on manipulator. Fig. 2. Devices for hardening of heavy crankshaft. Stage ooff Development The technology and equipment are commercially applied for hardening of surfaces of various parts. For example, the technology used for hardening of drill pipes (rods), large crankshafts (Fig.2), saws and knives provided a 2(cid:2) 3 times increase in their performance and a 3(cid:2)5 times decrease in power consumed for their manufacture. Novelty of the technology and equipment is covered by dozens of the USSR Author’s Certificates and Russian patents. Contact Details TYURIN Yuri E.O.Paton Electric Welding Institute NASU Tel.: (38 044) 289 09 14 Fax: (38 044) 271 20 34 E(cid:2)mail: ytyurin@i.com.ua http://www.i.com.ua/~ytyurin