Increasing the wear resistance of Al-Mg components using thermal-spray coatings

Abstract

In the present work, plasma-spray technology was applied as a means to improve the durability of Al-Mg alloy parts. NiCrSiBFe coatings deposited on aluminium-magnesium alloy substrates with different thickness values were studied. Before spraying, the surfaces of aluminium-magnesium alloy were modified upon applying different surface pre-treatment methods. The phase composition, microstructure, microhardness, porosity and adhesion of the deposited coatings were characterized. Ball-on-plate wear tests of the NiCrSiBFe coatings were carried out in dry and lubricated conditions, using a scanning electron microscope to characterize the worn track and the wear mechanism. The correlation of the coating porosity and the adhesion strength with the thickness of a deposited layer was determined. The results revealed that the plasma-sprayed NiCrSiBFe coatings, compared with the uncoated Al-Mg substrate, provide both a stable friction coefficient and an improved wear resistance, which is about two times better under dry sliding and about five times better under lubricated sliding. Keywords: aluminium-magnesium substrate, NiCrSiBFe coatings, plasma spray, sliding wear, adhesion strength V prikazanem delu je bila za izbolj{anje trajnosti delov iz Al-Mg zlitin uporabljena tehnologija pr{enja s plazmo. Predmet preu~evanja so bile NiCrSiBFe prevleke nanesene na podlago iz aluminij-magnezijevih zlitin. Pred nana{anjem so bile povr{ine aluminij-magnezijevih zlitin obdelane z razli~nimi postopki predpriprave povr{in. Dolo~ene so bile fazna sestava, mikrostruktura, mikrotrdota, poroznost in oprijem napr{enih prevlek. Za dolo~itev sledi obrabe in mehanizma je bil na NiCrSiBFe prevlekah izveden preizkus s kroglico, v suhih in naoljenih pogojih, in bil karakteriziran s pomo~jo vrsti~nega elektronskega mikroskopa. Dolo~ena je povezava med poroznostjo in jakostjo oprijema ter debelino nane{enega sloja. Rezultati so pokazali, da plazemsko napr{ene NiCrSiBFe prevleke v primerjavi z Al-Mg zlitino brez prevlek, omogo~ajo stabilen koeficient trenja in izbolj{ujejo odpornost, ki je dvakrat bolj{a pri drsenju po suhi podlagi, in petkrat bolj{a pri drsenju po naoljeni podlagi.

Investigation of tribological behavior of AA8011-ZrB2 in-situ cast-metal-matrix composites

“…AA8011 is widely used in the production of semi-rigid containers and in the packaging of foods and dairy products. [2][3][4][5][6] Aluminium composites are fabricated with various methods such as powder metallurgy, 7 vortex method, 8 squeeze casting, 9 stir casting ex situ, 10 thermal spray deposition, 11 laser surface alloying 12 and reactive process in situ. 13 The in-situ technique has an advantage over other techniques such as the economical, uniform distribution of reinforcements, grain refinements, clear interface, good interfacial bonding strength between the matrix and reinforcement without the need of a wetting agent and a high degree of thermal stability.…”

Effects of Electrolyte and Ti Layers on Static and Dynamic Friction of Anodized Alumina

“…Anodized aluminum surfaces have been thoroughly investigated, but mostly high purity aluminum was studied, whose nanopore arrays are highly uniform and symmetrical. Improvement of tribological properties of aluminum has always been important industrially [7]. Therefore, more attention has to be devoted to the nanopore distribution in industrial alloys.…”