Register to reply

High Temperature Super Alloys

Share this thread:
Pkruse
#1
Mar3-12, 09:15 AM
P: 490
Is anyone interested in starting a discussion on this topic? I use them in designs, but don't understand the metallurgy very well.

In particular, how does adding Al to Ni increase the melting point of Ni? It also improves a number of other desirable characteristics. The peak of the melting temperature curve on the phase diagram is at a 50-50 mixture. (Counting moles, not weight.) The resulting mixture is half aluminum, which we who work with refractory metals call "butter" due to its incredibly low melting point; yet the melting point of this mixture is much higher than pure Ni.
Phys.Org News Partner Engineering news on Phys.org
Student develops filter for clean water around the world
Developing the next evolution in underwater communication
Compact vibration harvester power supply with highest efficiency opens door to "fix-and-forget" sensor nodes
Astronuc
#2
Mar3-12, 09:39 AM
Admin
Astronuc's Avatar
P: 21,808
Quote Quote by Pkruse View Post
Is anyone interested in starting a discussion on this topic? I use them in designs, but don't understand the metallurgy very well.

In particular, how does adding Al to Ni increase the melting point of Ni? It also improves a number of other desirable characteristics. The peak of the melting temperature curve on the phase diagram is at a 50-50 mixture. (Counting moles, not weight.) The resulting mixture is half aluminum, which we who work with refractory metals call "butter" due to its incredibly low melting point; yet the melting point of this mixture is much higher than pure Ni.
Superalloys is an extraordinarily interesting topic, and in fact TMS (The Metallurgical Society) has hosted a conference Superalloys on a three year period. One of the key editors of the series, Ed Loria, passed away recently (http://www.physicsforums.com/showthread.php?t=402572).

TMS Superalloys Archive - http://knowledge.tms.org/superalloys.aspx

See also - http://www.tms.org/meetings/specialt...yshistory.html

The high melting point can be attributed to NiAl, an intermetallic compound.

See the Ni-Al phase diagram here - http://www.ias.ac.in/sadhana/Pdf2003Apr/Pe1064.pdf

The challenge is that there are several different phases that can form during the freezing of a melt, so one possibility is to produce a rapid solidified powder, which then must be hot pressed.
Pkruse
#3
Mar4-12, 08:05 AM
P: 490
Thanks, Joe. Now I have to go do some studying before I can ask further questions.


Register to reply

Related Discussions
Does anyone make a small high temperature and high pressure pump? General Engineering 0
What is the process called of heating alloys to High temperature for strength General Physics 6
Heat Treating of 800 Series High Nickle Alloys Mechanical Engineering 8
High temperature storage and temperature cycle TSV Copper sample Materials & Chemical Engineering 0
Stainless Steels and High Performance Alloys Materials & Chemical Engineering 2