Simultaneously enhanced strength and corrosion resistance of Mg–3Al–1Zn alloy sheets with nano-grained surface layer produced by sliding friction treatment

Friction treatment refers to surface strengthening (hardening) methods using highly concentrated energy sources. The source of thermal energy occurs in the contact area of the tool-part due to high-speed friction (60–90 m/s) of the tool on the treated surface. The heating rate of the metal surface layer is 105–106 K/s. After moving the energy source from the contact zone, high-speed cooling of the surface layer of the metal takes place. The cooling rate is 104–5∙105 K/s. Under the action of high-speed heating and cooling of the contact area of the tool-part in the surface layers, a strengthened (hardened) nanocrystalline (white) layer is formed. The formed nanocrystalline surface layer has other physical, mechanical, chemical properties in comparison with the base metal of the part. Studies have shown that in the process of friction treatment of working surfaces of parts made of Steel 40NiCr6 (quench hardening and low-temperature tempering) a strengthened layer with a thickness of 250–320 μm with a hardness of 7.6–9.2 GPa is formed. The grain size of the surface strengthened layer was 20–40 nm near the treated surface. The formation of the strengthened layer is influenced by the shape of the working surface of the tool. Thus, a strengthened layer of greater thickness and hardness is obtained when machining with a tool with transverse grooves on the working part than with a tool with a smooth working part. Experimental studies in friction with maximum lubrication of pair “Steel 40NiCr6 and Grey Cast Iron GG20” showed that the strengthened nanocrystalline layer significantly increases the performance during sliding friction. Only samples made of steel were strengthened, counter-samples made of gray cast iron were not strengthened. The wear intensity of strengthened pair is 2.2–3.1 times less compared to unstrengthened pair. During the friction of the strengthened pair, the coefficient of friction and the temperature in the sliding zone also decrease. The best results were obtained when studying the friction pair in which the samples were strengthened with a tool with transverse grooves on its working part.

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Microstructure, microtexture and precipitation in the ultrafine-grained surface layer of an Al-Zn-Mg-Cu alloy processed by sliding friction treatment

Materials Characterization ◽

10.1016/j.matchar.2016.11.021 ◽

2017 ◽

Vol 123 ◽

pp. 189-197 ◽

Cited By ~ 20

Author(s):

Yanxia Chen ◽

Yanqing Yang ◽

Zongqiang Feng ◽

Guangming Zhao ◽

Bin Huang ◽

...

Keyword(s):

Surface Layer ◽

Sliding Friction ◽

Cu Alloy ◽

Friction Treatment ◽

Ultrafine Grained

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Microstructure and Corrosion Behavior of Composite Coating on Pure Mg Acquired by Sliding Friction Treatment and Micro-Arc Oxidation

Materials ◽

10.3390/ma11071232 ◽

2018 ◽

Vol 11 (7) ◽

pp. 1232 ◽

Cited By ~ 7

Author(s):

Huihui Cao ◽

Wangtu Huo ◽

Shufang Ma ◽

Yusheng Zhang ◽

Lian Zhou

Keyword(s):

Corrosion Resistance ◽

Sliding Friction ◽

Corrosion Current ◽

Grain Structure ◽

Coarse Grained ◽

Fine Grained ◽

Friction Treatment ◽

Bonding Property ◽

Micro Arc Oxidation ◽

Superior Corrosion Resistance

For the purpose of detecting the influence of grain structure of a Mg matrix on the microstructure and corrosion resistance of micro-arc oxidation (MAO) coating, prior to MAO processing, sliding friction treatment (SFT) was adopted to generate a fine-grained (FG) layer on coarse-grained (CG) pure Mg surface. It showed that the FG layer had superior corrosion resistance, as compared to the CG matrix, owing to the grain refinement; furthermore, it successfully survived after MAO treatment. Thus, an excellent FG-MAO coating was gained by combining SFT and MAO. The surface morphology and element composition of FG-MAO and CG-MAO samples did not show significant changes. However, the FG layer favorably facilitated the formation of an excellent MAO coating, which possessed a superior bonding property and greater thickness. Consequently, the modified FG-MAO sample possessed enhanced corrosion resistance, since a lower hydrogen evolution rate, a larger impedance modulus and a lower corrosion current were observed on the FG-MAO sample.

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Microstructure and Mechanical Properties of Zamak 3 Alloy Subjected to Sliding Friction Treatment

Metallurgical and Materials Transactions A ◽

10.1007/s11661-019-05466-9 ◽

2019 ◽

Vol 50 (12) ◽

pp. 5888-5895 ◽

Cited By ~ 2

Author(s):

Wei Zhang ◽

Yan Du ◽

Wangtu Huo ◽

Jiangjiang Hu ◽

Jinwen Lu ◽

...

Keyword(s):

Mechanical Properties ◽

Sliding Friction ◽

Friction Treatment ◽

Microstructure And Mechanical Properties

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The Hybrid Process of Low-Pressure Carburizing and Metallization (Cr + LPC, Al + LPC) of 17CrNiMo7-6 and 10NiCrMo13-5 Steels

Coatings ◽

10.3390/coatings11050567 ◽

2021 ◽

Vol 11 (5) ◽

pp. 567

Author(s):

Paulina Kowalczyk ◽

Konrad Dybowski ◽

Bartłomiej Januszewicz ◽

Radomir Atraszkiewicz ◽

Marcin Makówka

Keyword(s):

Corrosion Resistance ◽

Surface Layer ◽

Physicochemical Properties ◽

Surface Treatment ◽

Retained Austenite ◽

Treatment Process ◽

Active Surface ◽

Low Pressure ◽

Low Alloy Steel ◽

Chromium Plating

This paper presents the concept of modification of physicochemical properties of steels by simultaneous diffusion saturation with carbon and chromium or aluminum. The application of a hybrid surface treatment process consisting of a combination of aluminizing and low-pressure carburizing (Al + LPC) resulted in a reduction in the amount of retained austenite in the surface layer of the steel. While the use of chromium plating and low-pressure carburizing (Cr + LPC) induced an improvement in the corrosion resistance of the carburized steels. It is of particular importance in case of vacuum processes after the application of which the active surface corrodes easily, as well as in case of carburizing of low-alloy steel with nickel, where an increased content of retained austenite in the surface layer is found after carburizing.

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Development of Nano-Structured Aluminum Surfaces by LSM

ASME 2008 2nd Multifunctional Nanocomposites and Nanomaterials ◽

10.1115/mn2008-47059 ◽

2008 ◽

Cited By ~ 1

Author(s):

Taha Mattar ◽

Ehab Abdel Rahman ◽

Ahmed Abdel-Aziz ◽

Haytham El-Gazzar

Keyword(s):

Corrosion Resistance ◽

Surface Layer ◽

Surface Structure ◽

Surface Melting ◽

Laser Surface ◽

Laser Surface Melting ◽

Aluminum Surface ◽

Yag Laser ◽

Structured Surface ◽

Aluminum Surfaces

Aluminum is one of most common metals in all advanced and modern scientific and technological applications including electrical, electronic, chemical, engineering, energy and medical fields. The performance of aluminum alloys determines to large extent the quality and economic status of the different processes. Aluminum surface structure determine its performance where nano sized grains and layer can improve aluminum properties and performance. In this work, the improvement of aluminum surface structure and formation of nano structured surface grains by laser surface melting (LSM) using Nd-YAG laser under argon atmosphere was investigated. Different power and scanning speed were applied. The physical and chemical properties of the produced surfaces were examined. SEM, EDX and XRD analyses were performed and were correlated to hardness results. Corrosion resistance of the treated surface was investigated to evaluate their performance in aggressive media and chemical and medical applications. From the obtained data it can be concluded that Nd-YAG laser surface melting of aluminum results in formation of 750 micron nano-structured surface layer. Adjustment of LSM parameters could produce 100 nm grains or less. The obtained results showed also that LSM under argon can eliminate the formation of Al2O3 surface layer which may deteriorates the performance in certain applications. Surface layer rich in AlN is formed upon LSM. It was concluded also that corrosion resistance of the treated aluminum surfaces was improved to large extent by LSM.

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