Alumunium Alloy with Nickel have better Heat resistance?

[Okaman]

Nice to meet you all =D
my name is Oka Mahendra, from Indonesia, currently working at NSK Bearing Manufacturing in Jakarta Plant as Failure Analysis and Investigation staff.

I want to ask to all material engineer about the Alumunium alloy. When Nickel is added to alumunium alloy, the heat resistance of the metals is increased. Why is this phenomena happening? Is it any correlation to the carbide forming (but i`m not sure, because in steel, nickel is not a carbide forming element), or is it the solubility limit to Alumunium? Sorry i can`t give any attachment regarding this question, but i`d like to discuss and gain knowledge about this topic.

Thank you for all your guidance and knowledge =D

 

[TVP]

Wrought alloys like 2618 and casting alloys like 242 and 336 have Cu and Ni added to them for increased strength at elevated temperature. This is attributed to the intermetallic precipitates that form, such as Al₂Cu and Al₃(Cu,Ni)₂. Here are one reference that you can review:

http://dunand.northwestern.edu/refs/files/YuLiLiZhao.pdf

 

[Okaman]

so the Al precipitate stable at high temperature? thank you TVP

 

[TVP]

Yes, some of the precipitates containing Cu and Ni have better thermal stability than those with Mg, Si, and Zn.

 

[Okaman]

do you think there are any correlation with the crystal structure and the solubility of Ni on Al?