Abstract

The objective of the given work was to investigate abrasive wear behaviours of titanium (Ti) treated by ultrasonic surface rolling processing (USRP) pre-treatment and plasma nitriding (PN). Simulated lunar regolith particles (SLRPs) were employed as abrasive materials during characterization of tribological performances. The experimental results showed that SLRPs cause severe abrasive wear on Ti plasma-nitrided at 750 °C via the mechanism of micro-cutting. Due to the formation of a harder and thicker nitriding layer, the abrasive wear resistance of the Ti plasma-nitrided at 850 °C was enhanced, and its wear mechanism was mainly fatigue. USRP pre-treatment was effective at enhancing the abrasive wear resistance of plasma-nitrided Ti, due to the enhancement of the hardness and thickness of the nitride layer. Nevertheless, SLRPs significantly decreased the friction coefficient of Ti treated by USRP pre-treatment and PN, because the rolling of small granular abrasives impeded the adhesion of the worn surface. Furthermore, USRP pre-treatment also caused the formation of a dimpled surface with a large number of micropores which can hold wear debris during tribo-tests, and finally, polishing and rolling the wear debris resulted in a low friction coefficient (about 0.5).

Highlights

  • For lunar exploration, micro-/nano-scaled lunar regolith particles that cover the surface of the moon always cause serious abrasive wear of a lunar rover [1,2,3,4,5]

  • ultrasonic surface rolling processing (USRP) pre-treatment is effective in enhancing the thickness of the nitride layer compared with the Ti directly treated by plasma nitriding

  • The Ti treated by USRP pre-treatment and plasma nitriding when sliding with abrasive Simulated lunar regolith particles (SLRPs)

Read more

Summary

Introduction

Micro-/nano-scaled lunar regolith particles that cover the surface of the moon always cause serious abrasive wear of a lunar rover [1,2,3,4,5]. A great number of surface treatments, for insistence, physical vapor deposition (PVD), chemical vapor deposition (CVD), surface texturing, laser deposition, surface alloying and ion implantation, and surface thermo-chemical treatment, have been introduced to improve the tribological properties of Ti and its alloy [8,10,11,12,13,14,15]. Among these surface treatments, many are limited by poor film–substrate cohesion, low processing efficiency and/or vast production cost. A novel surface modification method used to enhance abrasive wear resistance of lunar drilling devices is introduced

Materials and Surface Treatments
Micro-Structure and Micro-Hardness Characterization
Tribolo-tests
Microstructures of simulated lunarlunar regolith particles:
The diffraction of the a-Ti for the USRP
Typical
Micro-Hardness
Friction Coefficient
11. Abrasive
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call