PVD coating and substrate pretreatment concepts for magnesium alloys by multinary coatings based on Ti(X)N

Mechanical and corrosion properties of Al/Ti film on magnesium alloy AZ31B

“…In fact, DC-based coatings exhibit a columnar coating structure with some porosity between the columns [54]. Figures 1 and 2 demonstrate a structure and surface topography similar to the literature reported [54].…”

“…Figures 1 and 2 demonstrate a structure and surface topography similar to the literature reported [54]. Usually, the growth of the Al film on magnesium substrate contains nucleation, island formation and coalescence of islands, leading to the formation of pores, pinholes and channels in the Al film [55].…”

“…Usually, the growth of the Al film on magnesium substrate contains nucleation, island formation and coalescence of islands, leading to the formation of pores, pinholes and channels in the Al film [55]. The diffusion of adatoms along the deposited thin film surface could simultaneously occur, but the diffusion penetration into the thin film is normally ignored [54]. Thus, the diffusion of the Ti atoms into the Al layer may be neglected.…”

Composite titanium nitride layers produced on the AZ91D magnesium alloy by a hybrid method including hydrothermal modification of the layer

“…The effect of layers' hydrothermal tightening on the corrosion resistance was significantly more effective than thermal oxidation or oxynitriding in glow discharge conditions (430 • C/8-16 h) [13]. It is appropriate at this point to refer the results of the present study to the results obtained by other authors working with titanium nitrides surface layers on magnesium alloys [5,[14][15][16][17]. The results reported in the reference [14,15] indicate that TiN type titanium nitride layers resulted in a relatively low increase of corrosion resistance, with the corrosion potential shift almost an order of magnitude smaller than for the composite TiN-Ti-Al type titanium nitride layers that we developed.…”

“…They also fail to eliminate the risk of galvanic corrosion, related to their cathodic character, resulting in limited application prospects. It is only the most recent works carried out in this area by Hoche et al [5,16,17], that demonstrate significant potential of a solution based on producing titanium nitride coatings alloyed with magnesium (Ti-Mg-N and Ti-Mg-Al-N type layers), leading to a reduced difference in the chemical activity between the coatings and the magnesium substrate and, consequently, a reduced risk of galvanic corrosion. One should notice, however, that this type of solution does not make the coatings tight, unlike the hydrothermal tightening process that we have developed.…”