Microstructure and Properties of Electroless Ni-P/Si3N4 Nanocomposite Coatings Deposited on the AW-7075 Aluminum Alloy

The article presents the results of mechanical and tribological tests of Ni-P/Si3N4 nanocomposite coatings deposited on the AW-7075 aluminum alloy using the chemical reduction method. The influence of the chemical composition on the Vickers microhardness determined by the DSI method was examined. The nanocomposite layers were made of Si3N4 silicon nitride in a polydisperse powder with a particle size ranging from 20 to 25 nm. The influence of the content of the dispersion layer material on the adhesion to the substrate was analyzed. The abrasive wear was tested and determined in the reciprocating motion using the “ball-on-flat” method. The surface topography was examined by the contact method with the use of a profilometer. Based on the obtained test results, it was found that the Ni-P/Si3N4 layers produced in the bath with the Si3N4 nanoparticle content in the amount of 2 g/dm3 are more resistant to wear and show greater adhesion than the Ni-P/Si3N4 layers deposited in the bath with 5 g/dm3 of the dispersion phase. NiP/Si3N4 layers provide protection against abrasive wear under various loads and environmental conditions.

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Tribological Properties of Ni-P/Si3N4 Nanocomposite Layers Deposited by Chemical Reduction Method on Aluminum Alloy AW-7075

Materials ◽

10.3390/ma13245797 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5797

Author(s):

Kazimierz Czapczyk

Keyword(s):

Aluminum Alloy ◽

Abrasive Wear ◽

Reduction Method ◽

Chemical Reduction ◽

Contact Method ◽

7075 Aluminum Alloy ◽

Chemical Reduction Method ◽

Phase Layer ◽

Dispersion Phase ◽

7075 Alloy

The article presents the results of tribological tests of Ni-P/Si3N4 nanocomposite and Ni-P nickel layers deposited on the AW-7075 aluminum alloy by chemical reduction method, and the AW-7075 alloy without coating. Nanocomposite layers were produced using Si3N4 siliconnitride in the form of a polydisperse powder whose particle sizes ranged from 20 to 25 nm. The influence of the content of the dispersion phase layer material on the abrasive wear, which was determined as the “ball on disc” method, was analyzed. Surface topography was examined by the contact method using a profilometer. The purpose of introducing Si3N4 particles into the Ni-P layer was to increase the wear resistance of AW-7075 aluminum alloy parts with an embedded nanocomposite coating. Based on the obtained test results, it was found that the Ni-P/Si3N4 layers are more resistant to wear than the Ni-P layers and the AW-7075 alloy layers, and are a good barrier against abrasive wear at various loads and environmental conditions.

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Study of Damage Limit for Aluminum Alloy Plates with Surface Cracks under Cross-Thickness Bending

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.881-883.1365 ◽

2014 ◽

Vol 881-883 ◽

pp. 1365-1369

Author(s):

Hai Yang Yuan ◽

Yun Xin Wu ◽

Zhong Huai Wu ◽

Zhi Qi Liao

Keyword(s):

Aluminum Alloy ◽

7075 Aluminum Alloy ◽

Surface Cracks ◽

Test Results ◽

Entire Cross Section ◽

Reference Stress ◽

Bending Load ◽

Shallow Crack ◽

Deep Crack ◽

Good Agreement

A damage limit prediction model was built due to fracture failure problems of aluminum alloy plates. Based on the global plastic collapse of the entire cross-section containing the defect, the relationships of crack width and depth of fracturing 7075 aluminum alloy plates with either shallow crack or deep crack was analyzed by using reference stress method. The damage limit curves of 7075 aluminum alloy plates with crack was drew, and safety zone of crack propagation under corresponding bending load was confirmed. Then the experimental verification was carried out, results show that calculated results are in good agreement with the test results during the shallow crack stage, while in the deep crack stage experimental results are slightly less than calculated results.

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The influence of thickness of Ni-P layers produced on AW-7075 aluminum alloy on their adhesion and mechanical properties

Inżynieria Powierzchni ◽

10.5604/01.3001.0011.7933 ◽

2018 ◽

Vol 23 (1) ◽

pp. 18-26

Author(s):

Kazimierz Czapczyk ◽

Stanisław Legutko ◽

Piotr Siwak ◽

Karol Grochalski ◽

Anna Mazurek

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Light Microscopy ◽

Layer Thickness ◽

Reduction Method ◽

Chemical Reduction ◽

Mechanical Tests ◽

7075 Aluminum Alloy ◽

Chemical Reduction Method ◽

7075 Alloy

The article presents the results of mechanical tests of Ni-P layers deposited by the chemical reduction method on the AW-7075 aluminum alloy. The effect of layer thickness on hardness and microhardness of Vickers, which was determined by the DSI method, and their adhesion to the substrate by scratch method were investigated. The morphology was obtained using light microscopy and the topography of the examined layers using a contact profilometer. Different thicknesses were used to determine their effect on adhesion of the leyers to AW-7075 alloy. The results allowed to state that Ni-P layers of higher thickness are characterized by higher hardness and Young's modulus values than thinner Ni-P layers, and also show better adhesion to the AW-7075 alloy.

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