Vytváření hypereutektické Al slitiny nebo Ni aluminidů užitím Ni obětovatelných povlaků

Formation of Hypereutectic Aluminium-based Alloys or Nickel Aluminides Using Sacrificial Nickel Coatings

abstract

en

The contribution is focused on hypereutectic alloys or nickel aluminides formation, where was utilized the unconventional method consisted of (i) sacrificial coating deposition onto the substrate and (ii) subsequent heat treatment. The 99.7 wt.% Ni powder was used to produce the nickel coating, by means of high velocity oxyfuel spraying, onto the 99.999 wt.% Al sheet surfaces. Then the as-sprayed samples were heat treated up to the temperatures of 700, 900 and 1200oC. The heating/cooling rate of the samples of 5oC / min was set up. The hypereutectic alloys or nickel aluminides formation was investigated by using differential thermal analysis, metallography and scanning electron microscopy. To estimate the chemical composition of phases the energy dispersive microanalysis was used. The resulting microstructure of Al-Ni hypereutectic alloys originated up to the temperature of 900oC is of aluminium matrix and Al3Ni eutectic. Instead of that, the nickel aluminides were produced at the temperature of 1200oC and consist of Al3Ni2 and Al3Ni intermetallics. The image analysis was also applied to quantify the undissolved nickel coating thickness and parameters of eutectic.

The contribution is focused on hypereutectic alloys or nickel aluminides formation, where was utilized the unconventional method consisted of (i) sacrificial coating deposition onto the substrate and (ii) subsequent heat treatment. The 99.7 wt.% Ni powder was used to produce the nickel coating, by means of high velocity oxyfuel spraying, onto the 99.999 wt.% Al sheet surfaces. Then the as-sprayed samples were heat treated up to the temperatures of 700, 900 and 1200oC. The heating/cooling rate of the samples of 5oC / min was set up. The hypereutectic alloys or nickel aluminides formation was investigated by using differential thermal analysis, metallography and scanning electron microscopy. To estimate the chemical composition of phases the energy dispersive microanalysis was used. The resulting microstructure of Al-Ni hypereutectic alloys originated up to the temperature of 900oC is of aluminium matrix and Al3Ni eutectic. Instead of that, the nickel aluminides were produced at the temperature of 1200oC and consist of Al3Ni2 and Al3Ni intermetallics. The image analysis was also applied to quantify the undissolved nickel coating thickness and parameters of eutectic.

The contribution is focused on hypereutectic alloys or nickel aluminides formation, where was utilized the unconventional method consisted of (i) sacrificial coating deposition onto the substrate and (ii) subsequent heat treatment. The 99.7 wt.% Ni powder was used to produce the nickel coating, by means of high velocity oxyfuel spraying, onto the 99.999 wt.% Al sheet surfaces. Then the as-sprayed samples were heat treated up to the temperatures of 700, 900 and 1200oC. The heating/cooling rate of the samples of 5oC / min was set up. The hypereutectic alloys or nickel aluminides formation was investigated by using differential thermal analysis, metallography and scanning electron microscopy. To estimate the chemical composition of phases the energy dispersive microanalysis was used. The resulting microstructure of Al-Ni hypereutectic alloys originated up to the temperature of 900oC is of aluminium matrix and Al3Ni eutectic. Instead of that, the nickel aluminides were produced at the temperature of 1200oC and consist of Al3Ni2 and Al3Ni intermetallics. The image analysis was also applied to quantify the undissolved nickel coating thickness and parameters of eutectic.

hypereutectic alloy, nickel aluminides, nickel coatings

hypereutectic alloy, nickel aluminides, nickel coatings

03.09.2012

Materials Research Society of Serbia

Belgrade, Serbia

YUCOMAT 2012, The Book of Abstracts

14

39–39

1