Improvement of the hardness and wear resistance of (TiC, TiN)/Ti-6Al-4V surface-alloyed materials fabricated by high-energy electron-beam irradiation

Abstract

This study is concerned with the microstructural analysis and improvement of the hardness and wear resistance of Ti-6Al-4V surface-alloyed materials fabricated by a high-energy electron beam. The mixtures of TiC, TiN, or TiC ϩ TiN powders and CaF 2 flux were deposited on a Ti-6Al-4V substrate, and then the electron beam was irradiated on these mixtures. In the specimens processed with a flux addition, the surface-alloyed layers of 1 mm in thickness were homogeneously formed without defects and contained a large amount (over 30 vol pct) of precipitates such as TiC, TiN, (Ti x Al 1Ϫx )N, and Ti(C x N 1Ϫx ) in the martensitic or N-rich acicular ␣ -Ti matrix. This microstructural modification, including the formation of hard precipitates and hardened matrices in the surface-alloyed layers, improved the hardness and wear resistance. Particularly in the surface-alloyed material fabricated by the deposition of TiN powders, the wear resistance was greatly enhanced to a level 10 times higher than that of the Ti alloy substrate. These findings suggested that surface alloying using high-energy electron-beam irradiation was economical and useful for the development of titanium-based surfacealloyed materials with improved hardness and wear resistance.

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

“…This effect is due to the change of the heat input per unit area. According to [28], taking into account the reflection of electrons from the surface, the input energy per unit area is 2.89, 3.61 and 4.81 kJ/cm 2 at the speed of 25, 20 and 15 mm/s, respectively.…”

“…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.…”

Structure and properties of titanium surface layers after electron beam alloying with powder mixtures containing carbon

“…Laser [1][2][3][4][5][6][7] and electron beam processing [8][9][10][11][12][13][14][15][16] are the most widely used methods for this purpose. Many studies have proved the effectiveness of surface alloying of titanium alloys with carbon [1,12,16].…”

“…Laser cladding of TC4 titanium alloy (6.5 % Al, 4.26 % V, and Ti) with a powder mixture of titanium carbide (TiC) and titanium (Ti) resulted in a hardness of 1400 HV in the surface layer, which is 4.5 times the hardness of the substrate (300 HV) [17]. The starting material for surface alloying with carbon is typically a graphite powder [1,12,16,18] or a TiC powder [7,9,10,17,19,20].…”

Correlation of microstructure and abrasive and sliding wear resistance of (TiC,SiC)/Ti-6Al-4V surface composites fabricated by high-energy electron-beam irradiation

“…[1][2][3][4][5][6][7] Surface compositing is a fabrication method in which wear resistance, corrosion resistance, and thermal resistance can be enhanced by depositing desired elements on a substrate to form a composite layer. This method not only contributes to the development of new materials having excellent properties, but it also reduces production costs by compositing the surface only when fabricating alloys that require high-priced elements.…”