Tribological behavior of PS400-related tribopairs for space exploration

Tribological Behavior of Very Thin Confined Films

The tribological properties of two smooth surfaces in the presence of a thin confined film are investigated with a generic model for the interaction between two surfaces and with computer simulations. It is shown that at large normal contact pressures, an ultra thin film automatically leads to static friction between two flat surfaces-even if the surfaces are incommensurate. Commen-surability i...

Tribological behavior of sputter-deposited MoSX/Ni coatings

AbstractSputtered MoS2 coatings have been mostly used as a solid lubricant. In this investigation, MoSx/Ni composite coatings with Ni contents varying from 0 to 22 % were deposited onto steel substrate using a DC magnetron sputter process. The MoS2/Ni ratio in the coatings was controlled by sputtering the composite targets. The composition, microstructure, and mechanical properties of the...

Tribological Behavior of Reinforced and Unreinforced High Chromium Cast Iron

In this paper, the metal matrix composites containing 22 wt % Cr, 2.5 wt % C and 2 to 16  volume percent TiC were processed by solidifying Fe-Cr-Ti-C in which precipitation of titaniumcarbide and chromium carbide occurred. The microstructure and abrasion resistance of in-situ synthesized composites were compared with the unreinforced high chromium white cast iron (HCWCI) containing 22 w. t. % C...

Parameter Space Noise for Exploration

Deep reinforcement learning (RL) methods generally engage in exploratory behavior through noise injection in the action space. An alternative is to add noise directly to the agent’s parameters, which can lead to more consistent exploration and a richer set of behaviors. Methods such as evolutionary strategies use parameter perturbations, but discard all temporal structure in the process and req...

Nutrition issues for space exploration