Structure and Properties of Surface Layers Obtained by Atmospheric Electron Beam Cladding of Graphite-Titanium Powder Mixture onto Titanium Substrate

Abstract

The cladding of titanium and graphite powders on the cp-titanium workpieces using the electron beam injected to the atmosphere provided the formation of the surface layers with a high content of high-strength carbide particles. The main structural components in cladded layers are α-Ti (αʹ-Ti), titanium carbide and graphite. Electron beam current is the main technological parameter defining a thickness of the hardened layer. An increasing beam current ranged from 20 to 23 mA leads to the cladded layer growth up to 2.9 mm. However, in this case a significant decrease of the microhardness level and the wear resistance level of the cladded layer is not observed. An average microhardess value of the hardened layer is of 430 HV. Under the conditions of friction against fixed abrasive particles, a wear resistance level of the cladded layers is by 32-45 % larger than that of cp-titanium.

Structural Formation in the Zone of Interaction under Laser Processing of Bimetal M1 + VT1-0

“…Titanium alloys are prone to contact grasp during friction, regardless of the type and system of doping, as a result, to significant wear and mechanical damage to the contact surfaces. To improve tribotechnical properties of the parts made of titanium alloys, they typically use the same technologies for treating rubbing surfaces as for other metals: thermochemical treatment, electroplating, sputtering, laser and electric-spark surface doping, etc [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Analysis of studies in recent years, leads to the conclusion that traditional methods of increasing the wear resistance of products made of titanium and its alloys are ineffective.…”

Structure and Properties of Coatings Obtained by Electron-Beam Cladding of Ti+C and Ti+B₄C Powder Mixtures on Steel Specimens at Air Atmosphere

“…Crystallization of a melt after the electron-beam treatment occurs within short period of time. Rapid crystallization lead to formation of a special structures providing high hardness, wear resistance, contact fatigue endurance [7][8][9][10][11].…”

“…The choice of alloying components is the very important procedure for formation of materials with high mechanical and functional properties. It is well-known that the increase in the abrasive wear resistance can be reached by the formation of heterophase structures containing a large amount of carbides and borides in the surface layer [10][11][12]. Titanium is considered to be one of the most chemically active among all elements used for cladding that forms carbides in cooperation with carbon.…”

Structure and wear resistance of Ti-TiC-TiB layers obtained by non-vacuum electron beam cladding

“…Recently, a lot of studies have been devoted to improving the tribotechnical properties of titanium alloys by the formation of composite coatings on their surface (TMC -titanium matrix composites) using laser and electron beam technologies [6][7][8][9][10][11][12][13][14]. Particles of carbides, borides, and silicides of metals act as hardening components in these materials.…”

“…This technology is characterized by high performance and allows forming the coatings with a thickness of 1 to 3 mm [14,[22][23][24][25][26][27][28]. The microstructure, phase composition and tribotechnical tests of the coatings were investigated.…”