Discover endless possibilities with bi-metal components.

It is possible, by using proper procedures and with proper inertia/friction welding equipment,
to generate repeatable full strength welds in bi-metal applications.

Many metal combinations that are considered "not weldable" can in fact be joined using inertia welding.
Full strength bi-metal welds like the inertia welded parts shown here are used in a wide variety of product applications. On the Space Shuttle, for example, cryogenic fuel cells have caps that are made of inertia welded stainless steel to aluminum. Electrical connectors are also popular and often composed of copper and aluminum. Expand your solution with bimetals!

Materials Welded

One of the important characteristics of inertia welding is that it can join a wide variety of metals -- almost any metal that can be forged and that is not a good dry bearing material -- even some combinations that are difficult or impossible to weld any other way.

Some very difficult metal combinations can be joined because of certain fundamentals of the inertia welding process.

The tendency to form undesirable intermetallic compounds is reduced because welding temperatures do not exceed low solid state levels and because temperature peaks are of brief duration.

Another factor - oxidation, is never encountered, even with reactive materials since the two parts are in close contact all through the heating cycle.

Click to learn about the Inertia Welding Process →

Some of the classes of metals that can be successfully joined are:
  • COPPER

    • Stainless Steel
    • Steel
    • Titanium
  • ALUMINUM

    • Copper
    • Stainless Steel
    • Steel
    • Titanium
    • Tungsten
  • STAINLESS STEEL

    • Copper
    • Beryllium
    • Steel
    • Titanium
  • KOVAR/INVAR

    • Aluminum
    • Stainless Steel
    • Steel
  • ZIRCONIUM

    • Copper
    • Stainless Steel
    • Steel
    • Aluminum
  • INCONEL/MONEL

    • Copper
    • Stainless Steel
    • Steel
    • Aluminum

The combinations shown here are those that have already been commercially developed. See the link below to view a detailed list of materials and combinations that have been successfully inertia welded.

Bond Characteristics

Inertia/friction welding utilizes a high pressure forge force. Because of the high pressure, the metal, as it becomes heated by friction, is forged together with no melt product being produced, no chemical change and a very narrow heat affected zone.

This allows for a variety of metals that have different melt or sensitive chemistries to be joined with resulting properties that are excellent and comparable to the base metal.

Microscopic examination of the bond resulting from the inertia welding process reveals three metallurgical characteristics:

1. NARROW WELD ZONE

First, the weld zone is very narrow and has a fine-grained structure with no melt product or grain growth. This strong, refined structure results from vigorous hot working. When dissimilar metals are welded, there are frequently streaks of intermixed material near the outside of the diameter.

2. STRUCTURE BECOMES HARDENED

Second, hardening phases from the rapid chilling are seen throughout the structure. The degree of hardening can be controlled but is often about the same as that achieved with a mild water quench.

3. ORIGINAL MICROSTRUCTURES NEARLY RESTORED

Third, there is a zone of varying grain structure between the heat-affected zone and the parent structure. When a joint between identical materials is solution-heat-treated after welding, the weld zone is nearly restored to the original microstructures… it is difficult to find even with a microscope.