Many of the standard Nickel Aluminum Bronze Alloys are heat
treated per their alloy standard. The
heat treated alloys are as follows:
C63000 ASTM B150 HR50 AMS 4640
C95510 ASTM B505 AMS 4880
C63020 ASTM B150 AMS 4590
C95520 ASTM B505 AMS 4890
The reason for this is that heat treating these alloys can
have many beneficial effects to the metal.
They are as follows:
Relieve internal stress
Adjust tensile and hardness
Improve wear resistance
Reduce magnetic permeability
There are different methods of heat treating. Each with their own unique benefits and
This type of heat treatment is
used to relieve internal stress caused by cold working, rapid cooling, and/or
machining. Stress relieving of Nickel Aluminum Bronze is done at lower
temperatures than annealing. This is
really useful when the Nickel Aluminum Bronze is being machined into thinner
walled bushings, like those used in aircraft landing gears. As some Nickel Aluminum Bronze bar stock can
have a tendency to spring after larger amounts of metal is removed. By having the bar stock stress relieved, it
is less likely to spring out of tolerance after machining.
C63000 ASMT B150 AMS 4640 is
stress relieved and cold drawn in sizes up to 3” diameter. Being that this alloy is used extensively in bushing
applications, the stress relieving helps keep the close tolerance needed when
machining the bushings.
Generally this is done at a higher
temperature than stress relieving.
Annealing can cause a greater degree of microstructural change to the
metal. Recrystallization will normally
occur at temperatures above 1247° F.
Quenching and Tempering
Nickel Aluminum Bronze reacts
similarly to alloyed tool steels in respect to heat treatment procedures. A martensitic
phase is formed in the alloy when Nickel Aluminum Bronze is water quenched from
elevated temperatures. Once quenched
Nickel Aluminum Bronze Bars can be tempered to improve ductility while still
retaining a high tensile and hardness.
In alloy C63000 TQ50 AMS 4640,
this alloy is quenched hardened and temper annealed. C63000 bar stock above 3”
diameter is heat treated this way. This
gives this larger diameter greater tensile strength, improved hardness, at the
same time while improving the ductility of the metal.
C95510 is a cast alternative to
C63000. In this alloy heat treatment is
used to give this cast alloy similar mechanical properties to the extruded
version. This alloy is also quench hardened and temper annealed.
Heat treatment can be a useful
technique used to both relieve stress and improve mechanical properties in
Nickel Aluminum Bronze Alloys.
To learn more about our standard
Nickel Aluminum Bronze Alloys, follow the links below: