Understanding granular flows has always been important for predicting natural phenomena such as rockslides and soil erosion, as well as industrial processes such as coal-based fossil fuel systems and solids processing. As such, it becomes important to understand granular flows from both a classical granular flow and tribological perspective. Inherently important in the study of granular flows is the study of the individual particle level interactions, which define the global behavior of the flow. The current work examines both the coefficient of restitution (COR) and coefficient of friction (COF) for various material combinations. COR and tribological experiments are performed on various sphere and plate (disk) materials, such as low carbon steel, tungsten carbide (WC), and NITINOL 60.

Polishing of a nominally flat aluminum substrate using a fluid jet, carrying abrasive particles, was investigated. The effects of jet orientation and polishing duration were studied, on a fixed spot on the aluminum substrate. Stylus profilometry was used to examine the final surface along different directions. It was seen that the final erosion contour is strongly dependent on the jet orientation. The surface roughness was found to be dependent on the slurry parameters. On average, the average roughness (R a ) of the aluminum surface was reduced from 430 nm to 139 nm. Best polishing was obtained with the jet orientation of 30°. The process was simulated by using computational fluid dynamics (CFD), and it was concluded that dynamic pressure is the main parameter affecting erosion. Results apply to erosion as well as polishing of metal surfaces.

Erosion due to solid particles has a detrimental effect on the performance of components used in many critical applications. The problem becomes more acute at high temperatures. Thermal sprayed ceramic coatings are widely used in such situations wherein the present scenario considers better coatings. The ceramic composite coatings of alumina-zirconia were developed and their response to particle erosion and high temperature sliding wear and are experimentally evaluated. Based on a brittle erosion model, parametric influence on the variation of erosion rate was mathematically modeled adopting regression analysis and its validity is verified through a set of confirmation tests. Alumina-zirconia exhibits better performance with higher wear resistance and lesser coefficient of friction, at higher temperature, compared to plain alumina or alumina-titania.

The prediction of dishing and erosion caused by CMP is desired as they adversely affect the electrical properties of interconnects in integrated circuits. For a model to properly capture these phenomena, it must account for the time dependent surface evolution in CMP. This work employs the previously introduced Particle-Augmented Mixed Lubrication (PAML) model to predict dishing and erosion in CMP. By using PAML to model the polishing of a patterned wafer, it is possible to predict the dishing and erosion experienced during CMP.

The slurry erosion behaviors of pseudoelastic TiNi alloy were studied using the liquid/solid impingement system and compared with SUS 630 and 2Cr12NiMo1W1V alloy. The influences of erosion time and angle on erosion resistance of three materials were surveyed. The experimental results show that TiNi alloy has the highest erosion resistance among the three materials and SUS 630 stainless steel is more resistant than 2Cr12NiMoW1V alloy. The KQL-300 indentation tester was used to simulate the impact of particle on material surface during erosion process. The results show that the deformation mode of indention can be pile-up or sink-in and there is a good correlation between erosion resistance of material and its indentation deformation mode. The sink-in deformation mode indicates the higher resistance to erosion, and the pile-up deformation mode implies the lower erosion resistance.