Amphiphilic Zirconium Phosphate Nanoparticles as Tribo-catalytic Additives of Multi-performance Lubricants

2021 ◽  
pp. 1-8
Author(s):  
Yan Chen ◽  
Xuezhen Wang ◽  
Zehua Han ◽  
Alexander Sinyukov ◽  
Abraham Clearfield ◽  
...  
Keyword(s):  
Material Removal ◽  
Zirconium Phosphate ◽  
Surface Characterization ◽  
Film Growth ◽  
Removal Rate ◽  
The Coefficient Of Friction ◽  
And Performance ◽  
Catalytic Additives

Abstract The advancement of electric vehicles demands lubricants with multifunction and performance. In this research, we investigated amphiphilic a-ZrP nanoparticles as lubricant additives. Experimetns showed that the nanolubricant produced a tribofilm reduced the friction for 40% and wear 90%, while the electrical conductivity remained to be stable during tribotesting. Surface characterization of the tribofilm showed that there was a layered pyrophosphate on the wear track . The in situ impedance study about tribochemical kinetics revealed that the process in formation of a tribofilm involved synergetic growth and wear. During growth, the coefficient of friction increased with continued formation of such a file. During wear, the material removal rate was a function of friction, i.e., the higher the wear rate, the higher the friction coefficient. The competing mechanisms of film growth and wear resulted in an electrically uniformed surface.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Experimental Investigation on Wafer Polishing of Oxide and Copper Layers

2002 ◽  
Author(s):  
Jhy-Cherng Tsai
Keyword(s):  
Process Parameters ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Back Pressure ◽  
Copper Layer ◽  
Wafer Polishing ◽  
Critical Technology ◽  
And Performance ◽  
Polishing Pressure

Polishing, in particular chemical-mechanical polishing (CMP), is a critical technology for the planarization of wafers. This paper investigates, via experiments, and compares the performance of CMP process with different process parameters for wafers with silicon-dioxide (SiO2) layer and for wafers with copper (Cu) layer. Polishing pressure (P), speed (V), and back pressure (BP) are used as process parameters in this study. Different pads and slurries are also experimented for copper layer as its properties are different from that of conventional oxide layer. Material removal rate (RR) and non-uniformity (NU) are used as indices to measure the performance. Experimental data on oxide layers show RR increases as P and V increase but NU gets worse at the same time. This condition can be improved, for both oxide and copper layers, with suitable BP. Experiments on copper CMP using slurry with abrasives show that RR increases with higher P and V. While NU gets worse with higher P, it can be reduced as V increases using a soft pad. Better NU can be obtained using soft pad though RR is lower in this case. For abrasive-free polishing of copper layer, RR, though relatively lower compared to CMP with regular slurry, is unstable using hard pad despite that NU becomes better at higher P. NU of polished wafer is best at certain pressure but becomes worse at low pressure for hard pad and at high P for soft pad. It is also observed that NU of AFP can be improved with BP and softer pad. Soft pad gives better polishing quality and performance though RR is lower than that using slurry with abrasives.

scholarly journals Numerical Modeling for Engineering Analysis and Designing of Optimum Support Systems for Headrace Tunnel

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Sajjad Hussain ◽  
Zahid Ur Rehman ◽  
Noor Mohammad ◽  
Muhammad Tahir ◽  
Khan Shahzada ◽  
...  
Keyword(s):  
Rock Mass ◽  
Support Systems ◽  
Research Work ◽  
Strength Properties ◽  
Efficient Design ◽  
Headrace Tunnel ◽  
And Performance ◽  
Selection Of

The empirical and numerical design approaches are considered very important in the viable and efficient design of support systems, stability analysis for tunnel, and underground excavations. In the present research work, the rock mass rating (RMR) and tunneling quality index (Q-system) were used as empirical methods for characterization of rock mass based on real-time geological and site geotechnical data and physical and strength properties of rock samples collected from the alignment of tunnel. The rock mass along the tunnel axis was classified into three geotechnical units (GU-1, GU-2, and GU-3). The support systems for each geotechnical unit were designed. The 2D elastoplastic finite-element method (FEM) was used for the analysis of rock mass behavior, in situ and redistribution stresses, plastic thickness around the tunnel, and performance of the design supports for the selection of optimum support system among RMR and Q supports for each geotechnical unit of tunnel. Based on results, Q support systems were found more effective for GU-1 and GU-2 as compared to RMR support systems and RMR support systems for GU-3 as compared to Q support systems.

Functional Filtering and Performance Correlation of Plateau Honed Surface Profiles

2005 ◽  
Vol 127 (1) ◽  
pp. 193-197 ◽  
Author(s):  
B. Muralikrishnan ◽  
J. Raja
Keyword(s):  
Surface Characterization ◽  
Cylinder Liner ◽  
Core Layer ◽  
Complex Nature ◽  
Morphological Filters ◽  
Effect Model ◽  
Liner Surface ◽  
Surface Profiles ◽  
And Performance

Plateau honing produces a unique texture on cylinder liner surface. This surface is engineered to simulate the actual running in process of the engine and results in a core layer superimposed on valleys. Because of the complex nature of the surface, characterization of such surfaces is very different from traditional surface texture analysis. Different filtering techniques have been employed to remove waviness from these profiles. Parameters are subsequently computed from the bearing area curve of the roughness profile. With recent progress in filtering of surface profiles, we propose a functional analysis approach based on morphological filters. The advantage of this technique is the clear separation of the core texture from the valleys resulting in better correlation with process and functional measures. A number of profiles are collected from two sets of liners with different performance characteristics. A cause effect model is built and used for performance prediction.

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