Formation of gradient microstructure and mechanical properties of hot-pressed W-20 wt% Cu composites after sliding friction severe deformation

Abstract

W-based alloys are currently considered promising candidates for high heat flux components in future fusion reactors. In this paper, hot pressed W-20wt.%Cu composites were treated at room temperature using a sliding friction severe deformation (SFD) process, with a moving speed of 0.2 m/s and an applied load of 500 N. Microstructural evolution of composites after the SFD treatment was evaluated and compared with that of the untreated composites. Results showed that there was a gradient structure generated and an obvious refinement in tungsten particles size in

The process of surface carburization and high temperature wear behavior of infiltrated W-Cu composites

“…10 curves (b) and 4 (d), the friction coefficient of the carburized layer is relatively smaller under the high 5 temperature. The hardness value of the surface carburized layer is much higher than 6 that of the un-carburized composites (see Table 2). Also it is well-known that the carbon 7 (graphite) has a good self-lubricating effect, thus the friction coefficient can be further 8 reduced during tests.…”

“…This treatment had effectively 2 improved the surface hardness of armor piercing bullets, whereas the core of the 3 projectile could be easily broken under a high-speed impact, thus improving its self- 4 sharpening performance and enhancing its piercing ability, which was reported by Jung 5 et al [15]. 6 However, to the best of our knowledge, there is no any report on the study of the 7 carburization behavior and mechanism of W-Cu composites so far, experimentally or 8 theoretically. In the present study, we will focus our work on solid carburization of the 9 W-20wt.% Cu composites and for the first time; identify their behavior against high 10 temperature friction and wear.…”

“…Tungsten copper (W-Cu) composites is a non-miscible pseudo-alloy which consist 20 of mixed W and Cu phases and is generally produced using a powder metallurgy 21 technology [1][2]. It has numerous good properties, such as good resistance to arc 22 erosion, good machinability, relatively high strength, and good thermal conductivity, 23 thus has been widely used in electronic seals, high-voltage electrical contacts [3], 24 3 electromagnetic railway [4], nozzle throat for rocket engine [5] and oval hole guide for 1 the precision rolling mill [6][7]. However, failure of components during service was 2 frequently initiated from the surface of the composites components, especially when 3 there are various types of surface defects [8][9].…”

“…However, failure of components during service was 2 frequently initiated from the surface of the composites components, especially when 3 there are various types of surface defects [8][9]. Due to the lower melting point and 4 cooling effect of Cu and the high melting point and high strength of W, W-Cu 5 composites generally show a good performance when they are used as guides and 6 guarding materials. However, they often show premature failures due to their 7 insufficient surface hardness [10].…”

“…The size of sample was 5.25 mm × 9.97 mm × 24.6 mm. The bending strength 6 was calculated according to the following equation [18]:…”