scholarly journals Effect of Cavitation Erosion Wear, Vibration Tumbling, and Heat Treatment on Additively Manufactured Surface Quality and Properties

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1540 ◽  
Author(s):  
Sergey N. Grigoriev ◽  
Alexander S. Metel ◽  
Tatiana V. Tarasova ◽  
Anastasia A. Filatova ◽  
Sergey K. Sundukov ◽  
...  
Keyword(s):  
Surface Quality ◽  
Cavitation Erosion ◽  
Roughness Parameter ◽  
Erosion Wear ◽  
Post Processing ◽  
Heat Treated ◽  
Abrasive Finishing ◽  
Aisi 321 ◽  
Measured Hardness ◽  
Austenitic Class

The paper is devoted to researching various post-processing methods that affect surface quality, physical properties, and mechanical properties of laser additively manufactured steel parts. The samples made of two types of anticorrosion steels—20kH13 (DIN 1.4021, X20Cr13, AISI 420) and 12kH18N9T (DIN 1.4541, X10CrNiTi18-10, AISI 321) steels—of martensitic and austenitic class were subjected to cavitation abrasive finishing and vibration tumbling. The roughness parameter Ra was reduced by 4.2 times for the 20kH13 (X20Cr13) sample by cavitation-abrasive finishing when the roughness parameter Ra for 12kH18N9T (X10CrNiTi18-10) sample was reduced by 2.8 times by vibratory tumbling. The factors of cavitation-abrasive finishing were quantitatively evaluated and mathematically supported. The samples after low tempering at 240 °C in air, at 680 °C in oil, and annealing at 760 °C in air were compared with cast samples after quenching at 1030 °C and tempering at 240 °C in air, 680 °C in oil. It was shown that the strength characteristics increased by ~15% for 20kH13 (X20Cr13) steel and ~20% for 12kH18N9T (X10CrNiTi18-10) steel than for traditionally heat-treated cast samples. The wear resistance of 20kH13 (X20Cr13) steel during abrasive wear correlated with measured hardness and decreased with an increase in tempering temperatures.

scholarly journals Fatigue Behavior of Non-Optimized Laser-Cut Medical Grade Ti-6Al-4V-ELI Sheets and the Effects of Mechanical Post-Processing

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 843 ◽  
Author(s):  
André Reck ◽  
André Till Zeuner ◽  
Martina Zimmermann
Keyword(s):  
Surface Roughness ◽  
Fatigue Strength ◽  
Surface Quality ◽  
Laser Cutting ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Surface Condition ◽  
Mechanical Polishing ◽  
Fatigue Properties ◽  
Post Processing

The study presented investigates the fatigue strength of the (α+β) Ti-6Al-4V-ELI titanium alloy processed by laser cutting with and without mechanical post-processing. The surface quality and possible notch effects as a consequence of non-optimized intermediate cutting parameters are characterized and evaluated. The microstructural changes in the heat-affected zone (HAZ) are documented in detail and compared to samples with a mechanically post-processed (barrel grinding, mechanical polishing) surface condition. The obtained results show a significant increase (≈50%) in fatigue strength due to mechanical post-processing correlating with decreased surface roughness and minimized notch effects when compared to the surface quality of the non-optimized laser cutting. The martensitic α’-phase is detected in the HAZ with the formation of distinctive zones compared to the initial equiaxial α+β microstructure. The HAZ could be removed up to 50% by means of barrel grinding and up to 100% through mechanical polishing. A fracture analysis revealed that the fatigue cracks always initiate on the laser-cut edges in the as-cut surface condition, which could be assigned to an irregular macro and micro-notch relief. However, the typical characteristics of the non-optimized laser cutting process (melting drops and significant higher surface roughness) lead to early fatigue failure. The fatigue cracks solely started from the micro-notches of the surface relief and not from the dross. As a consequence, the fatigue properties are dominated by these notches, which lead to significant scatter, as well as decreased fatigue strength compared to the surface conditions with mechanical finishing and better surface quality. With optimized laser-cutting conditions, HAZ will be minimized, and surface roughness strongly decreased, which will lead to significantly improved fatigue strength.

Investigation on the Improvement of Surface Quality by the Magnetic Plate-Assisted Magnetic Abrasive Finishing Process

2021 ◽  
Vol 1018 ◽  
pp. 111-116
Author(s):  
Yan Hua Zou ◽  
Hui Jun Xie
Keyword(s):  
Magnetic Field ◽  
Surface Quality ◽  
Field Distribution ◽  
Magnetic Field Distribution ◽  
Magnetic Flux Density ◽  
Magnetic Pole ◽  
Magnetic Abrasive Finishing ◽  
Abrasive Finishing ◽  
Glass Lens ◽  
The Magnetic Field

The traditional magnetic abrasive finishing (MAF) process, the magnetic flux density at the bottom of the magnetic pole is unevenly distributed, resulting in poor uniformity of the finished surface. Therefore, it is proposed to improve the surface quality by attaching a magnetic plate at the bottom of the workpiece to improve the magnetic field distribution. It is confirmed by simulation that the magnetic field distribution at the bottom of the magnetic pole is effectively improved after the magnetic plate is attached. It is proved through experiments that the magnetic plate-assisted MAF process can obtain a smoother surface. The experimental results show that the surface roughness of the glass lens improves from 246 nm Ra to 3 nm Ra through the magnetic plate-assisted MAF process within 45min.

New Results of the Heat-Treated CuZn39Pb3 Brass Behavior and Resistance to Cavitation Erosion

2021 ◽  
Vol 890 ◽  
pp. 173-180
Author(s):  
Ilare Bordeaşu ◽  
Nicușor Alin Sîrbu ◽  
Iosif Lazăr ◽  
Ion Mitelea ◽  
Cristian Ghera ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cavitation Erosion ◽  
Stress Relief ◽  
Air Cooling ◽  
Water Cooling ◽  
Characteristic Parameters ◽  
Volume Heat ◽  
Heat Treated ◽  
Hardness Increase

The paper presents the results of the behavior and resistance to the erosion by vibrating cavitation of the CuZn39Pb3 brass, obtained by quenching the volume heat treatment from 800°C with water cooling, followed by the stress-relief to 250°C, with air cooling. Comparison with both the delivery status and the naval brass (used for ship propellers), based on the characteristic parameters values, recommended by the ASTM G32 standards and used in the Cavitation Laboratory of the Polytechnic University of Timisoara, shows that the hardness increase resulted from the heat treatment led to a significant increase of resistance to vibrating cavitation.

Effect of Hardness of Needle-Sealing Surface of Pintle Nozzle on Cavitation Erosion

2011 ◽  
Vol 130-134 ◽  
pp. 946-949
Author(s):  
Heng Zhou Wo ◽  
Ya Fang Zhang ◽  
Xian Guo Hu ◽  
Yu Fu Xu
Keyword(s):  
Diesel Engine ◽  
Cavitation Erosion ◽  
Surface Hardness ◽  
Lower Surface ◽  
Important Influence ◽  
The Other ◽  
Power Performance ◽  
Fuel Atomization ◽  
Heat Treated

Nozzle is one of key parts in the diesel engine. The cavitation erosion of needle-sealing surface in the pintle nozzle has important influence on the fuel atomization, combustion and power performance of diesel engine. In order to investigate the effect of hardness of needle-sealing surface on cavitation erosion, two kinds of nozzles were selected and operated in S195 diesel engine for 10 hours. One nozzle is heat-treated one which has lower surface hardness; the other with higher surface hardness is real commercial nozzle. The surface appearances of original and operated nozzle-sealing surface were observed by SEM. It was found that the cavitation erosion on the seal surface of nozzle with lower hardness was severer than that of nozzle with higher hardness. However, their wear ways and formations are similar.

Research on Surface Quality Enhancement of Wood-Plastic Composite Powder SLS Parts by Post Processing

2010 ◽  
Vol 113-116 ◽  
pp. 508-511 ◽  
Author(s):  
Wei Liang Zeng ◽  
Yan Ling Guo
Keyword(s):  
Surface Quality ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Wood Plastic Composite ◽  
Post Processing ◽  
Plastic Composite ◽  
Rp Process ◽  
Sintering Properties

According to its advantages, such as low-cost and green biological etc., Wood-Plastic Composite(WPC) is more suitable for make parts by Selective Laser Sintering(SLS) rapid prototyping (RP) process. With optimal design of components, the parts made by WPC have good mechanical properties as well as with good laser sintering properties. In order to further improve the surface quality of the parts, the post-processing–infiltrating with wax–is introduced. After post-processing, the void fraction is decreased from 51% to 7%, surface quality has been greatly improved, Ra belows 13µm on average, after polishing the surface is more smooth and Ra belows 5µm averagely，compared to those without post processing, surface roughness decrease 22% and 73% respectively.

scholarly journals The morphology of cavitation damage of heat-treated medium carbon steel

2006 ◽  
Vol 71 (8-9) ◽  
pp. 977-984 ◽  
Author(s):  
Marina Dojcinovic ◽  
Srdjan Markovic
Keyword(s):  
Carbon Steel ◽  
Cavitation Erosion ◽  
Medium Carbon Steel ◽  
Cavitation Damage ◽  
Medium Carbon ◽  
Erosion Rates ◽  
Hydraulic Machinery ◽  
Heat Treated ◽  
Set Up ◽  
Microscopy Techniques

In this paper the morphology of the cavitation damage to heat-treated medium carbon steel was analyzed. The experiments were conducted using a modified vibratory cavitation test set up. The erosion rates were measured by an analytical method. The morphology of the cavitation damage was studied by the scanning electron microscopy and optical microscopy techniques. The present work was aimed at understanding the cavitation erosion behavior of heat-treated medium carbon steel under laboratory conditions. The results indicate that the heat-treated medium carbon steel is not to be recommended for the production of hydraulic machinery parts exposed to high hydrodynamic intensity.

Effect of the Platinum Electroplated Layer Thickness on the Coatings’ Microstructure

2017 ◽  
Vol 36 (3) ◽  
pp. 291-297
Author(s):  
Maryana Zagula-Yavorska ◽  
Kamil Gancarczyk ◽  
Jan Sieniawski
Keyword(s):  
Heat Treatment ◽  
Diffusion Zone ◽  
Roughness Parameter ◽  
Inconel 625 ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Inconel 625 Superalloy ◽  
Two Phases ◽  
Electroplating Process

AbstractCMSX 4 and Inconel 625 superalloys were coated by platinum layers (3 and 7 μm thick) in the electroplating process. The heat treatment of platinum layers (at 1,050 ˚C for 2 h) was performed to increase platinum adherence to the superalloys substrate. The diffusion zone obtained on CMSX 4 superalloy (3 and 7 μm platinum thick before heat treatment) consisted of two phases: γ-Ni(Al, Cr) and (Al0.25Pt0.75)Ni3. The diffusion zone obtained on Inconel 625 superalloy (3 μm platinum thick before heat treatment) consisted of the α-Pt(Ni, Cr, Al) phase. Moreover, γ-Ni(Cr, Al) phase was identified. The X-ray diffraction (XRD) results revealed the presence of platinum in the diffusion zone of the heat-treated coating (7 μm platinum thick) on Inconel 625 superalloy. The surface roughness parameter Ra of heat-treated coatings increased with the increase of platinum layers thickness. This was due to the unequal mass flow of platinum and nickel.

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