Waterjet Peening and Surface Preparation at 600MPa: A Preliminary Experimental Study

2006 ◽  
Vol 129 (4) ◽  
pp. 485-490 ◽  
Author(s):  
A. Chillman ◽  
M. Ramulu ◽  
M. Hashish
Keyword(s):  
Experimental Study ◽  
Plastic Deformation ◽  
High Pressure ◽  
Subsurface Layer ◽  
Surface Preparation ◽  
Material Surface ◽  
Ultra High Pressure ◽  
Shock Peening ◽  
Droplet Impacts ◽  
Compressive Residual Stresses

An experimental study was conducted to explore the surface preparation as well as the effects of high-pressure waterjet peening at 600MPa on the surface integrity and finish of metals. The concept of larger droplet size and multiple droplet impacts resulting from an ultra-high-pressure waterjet was used to explore and develop the peening process. A combination of microstructure analysis, microhardness measurements, and profilometry were used in determining the depth of plastic deformation and surface finish that result from the surface treatment process. It was found that waterjet peening at 600MPa induces plastic deformation to greater depths in the subsurface layer of metals than laser shock peening. The degree of plastic deformation and the state of the material surface were found to be strongly dependent on the peening conditions and desired surface roughness. Based on these first investigation results, water peening at 600MPa may serve as a new method for introducing compressive residual stresses in engineering components.

Waterjet Peening At 600MPa: A First Investigation

2005 ◽  
Author(s):  
M. Hashsish ◽  
A. Chillman ◽  
M. Ramulu
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Treatment Process ◽  
Laser Shock Peening ◽  
Material Surface ◽  
Laser Shock ◽  
Ultra High Pressure ◽  
Shock Peening ◽  
Droplet Impacts ◽  
Compressive Residual Stresses

An experimental study was conducted to explore the high-pressure waterjet (WJ) peening at 600MPa on the surface integrity and texture of metals. The concept of larger droplet size and multiple droplet impacts resulting from an ultra high-pressure waterjet (UHPWJ) was used to explore and develop the peening process. A combination of microstructure analysis, microhardness measurements, and profilometry were used in determining the depth of plastic deformation and surface texture that result from the surface treatment process. It was found that waterjet peening at 600MPa induces plastic deformation to greater depths in the sub-surface layer of metals than laser shock peening. The degree of plastic deformation and the state of material surface were found to be strongly dependent on the peening conditions and desired surface roughness. Based on these first investigation results, water peening at 600MPa may serve as a new method for introducing compressive residual stresses in engineering components.

scholarly journals A numerical and experimental study of oblique impact of ultra-high pressure abrasive water jet

2016 ◽  
Vol 8 (3) ◽  
pp. 168781401663679 ◽  
Author(s):  
Can Kang ◽  
Haixia Liu ◽  
Xiuge Li ◽  
Ya Zhou ◽  
Xiaonong Cheng
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Oblique Impact ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Ultra High Pressure

Mathematical Modeling of Ultra-High-Pressure Waterjet Peening

2005 ◽  
Vol 127 (2) ◽  
pp. 186-191 ◽  
Author(s):  
S. Kunaporn ◽  
M. Ramulu ◽  
M. Hashish
Keyword(s):  
Mathematical Modeling ◽  
High Pressure ◽  
High Cycle Fatigue ◽  
Fatigue Tests ◽  
Analytical Models ◽  
Test Results ◽  
Ultra High Pressure ◽  
Proposed Model ◽  
Compressive Residual Stresses ◽  
Good Agreement

Waterjet peening is a recent promising method in surface treatment. It has the potential to induce compressive residual stresses that benefit the fatigue life of materials similar to the conventional shot peening process. However, there are no analytical models that incorporate process parameters (i.e., supply pressure, jet exposure time, and nozzle traverse rate, etc) to allow predicting the optimized peening process. Mathematical modeling of high-pressure waterjet peening was developed in this study to describe the relation between the waterjet peening parameters and the resulting material modifications. Results showed the possibility of using the proposed mathematical model to predict an initial range for effective waterjet peening under the variation of waterjet peening conditions. The high cycle fatigue tests were performed to validate the proposed model and fatigue test results showed good agreement with the predictions.

Energy Based Modeling of Ultra High-Pressure Waterjet Surface Preparation Processes

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
A. Chillman ◽  
M. Hashish ◽  
M. Ramulu
Keyword(s):  
High Pressure ◽  
Energy Density ◽  
Power Distribution ◽  
Experimental Studies ◽  
Surface Texturing ◽  
Surface Preparation ◽  
Orifice Diameter ◽  
Net Energy ◽  
Ultra High Pressure ◽  
Impulse Pressure

Ultra high-pressure waterjets (UHP-WJ) have been emerging as a viable method for surface texturing, cleaning, and peening of metallic materials. Previous experimental studies have suggested that removal of material can be related to the energy density of the waterjet impinging upon the workpiece, rather than the net energy. The net energy transferred to the workpiece is a function of four key process parameters, namely, (i) orifice diameter, (ii) orifice geometry, (iii) supply pressure, and (iv) traverse rate. The energy density also incorporates jet spreading as well as flow rate and impulse pressure distributions within the waterjet. In this paper, a novel representation of the power distribution within the waterjet is presented, as well as a relationship governing jet-material interaction. Empirical validation on a Ti-6Al-4V titanium alloy is presented, with good correlation noted between the predicted and experimental results.

K-cymrite as Redox Insensitive Transporter of Nitrogen in the Mantle

2020 ◽  
Author(s):  
Alexander Sokol ◽  
Igor Kupriyanov ◽  
Yurii Seryotkin ◽  
Ella Sokol
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Hydrogen Atom ◽  
Subduction Zones ◽  
Storage Capacity ◽  
Russian Science ◽  
Silicate Minerals ◽  
Ultra High Pressure ◽  
Ocean Ridges

<p>The current flux of nitrogen into the mantle in subduction zones is about three times its amount outgassing at mid-ocean ridges, arc and intraplate volcanoes, i.e., some efficient nitrogen hosts and carriers should exist in slabs. The K<sup>+</sup> → (NH<sub>4</sub><sup>+</sup>) substitution in silicate minerals is possible only within limited redox-favorable parts of slabs. Whether nitrogen can be transported and immobilized in the mantle as part of solids by some redox-independent mechanisms? The experimental study of the muscovite-NH<sub>3</sub>-N<sub>2</sub>-H<sub>2</sub>O and eclogite+muscovite-NH<sub>3</sub>-N<sub>2</sub>-H<sub>2</sub>O systems at 6.3-7.8 GPa and 1000 to 1200°C shows that NH<sub>3</sub>- and N<sub>2</sub>-rich K-cymrite can be stable in metapelite and act as a redox insensitive carrier of nitrogen to mantle depths >200 km in downgoing slabs. This ability is related to its unique clathrate structure that can accommodate three species of nitrogen: N<sub>2</sub> and NH<sub>3</sub> molecules in cages and (NH<sub>4</sub>)<sup>+</sup> substituting for K<sup>+</sup>, while imprisoned N<sub>2</sub> and NH<sub>3</sub> were first discovered in cages of ultra-high pressure minerals. The storage capacity K-cymrite with respect to nitrogen increases from 2.9 to 6.3 wt.% with increase of fO<sub>2 </sub>from ~IW to ~NNO, at the N<sub>2</sub>/(NH<sub>3</sub>+N<sub>2</sub>) ratio in fluid from 0.1 to 0.9. Comparison of equilibrated muscovite and K-cymrite synthesized at 7.8 GPa, 1070°C, and fO<sub>2 </sub>~IW demonstrates that the clathrate mechanism of nitrogen entrapment by aluminosilicates (in the form of N<sub>2</sub> and NH<sub>3 </sub>molecules) is much more efficient than the K<sup>+ </sup>® (NH<sub>4</sub><sup>+</sup>) substitution even in strongly reduced conditions. The presence of an N-bearing fluid in the studied systems stabilizes the K-cymrite structure. Muscovite does not convert to K-cymrite in the absence of NH<sub>3</sub>-N<sub>2</sub>-bearing fluid within 7.8 GPa and 1070-1120°C. Our estimates of normalized volume per non-hydrogen atom show that N<sub>2</sub>-bearing cymrite is the densest in the series of K-cymrite with cages filled to different degrees: K-Cym<sub>NH3</sub> > K-Cym<sub>H2O</sub> > K-Cym<sub>N2</sub> and is thus the most stable among cymrite-type compounds under high pressure.</p><p><em>The research was performed by a grant of the Russian Science Foundation (16-17-10041).</em></p>

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