Friction Bit Joining

National Laboratory: 
Oak Ridge National Laboratory
Processing/Manufacturing Class: 
Joining
Description: 

Oak Ridge National Laboratory has a unique capability known as friction bit joining (FBJ), a solid-state process for joining dissimilar materials (e.g., aluminum/steel, polymer/steel, or magnesium alloy/steel). The process uses a consumable joining bit that serves as plunging and joining roles during FBJ. During the joining stage, the bit and surrounding sheet materials are heated by friction, leading to solid-state bonding.

Capability Bounds: 

The machine can join different material combinations with a coupon scale. Based on the joining bit’s length, it is possible to join materials with different thicknesses (1~6 mm). The equipment’s maximum tool rotational speed is 4000 rpm, and constant stall torque is 19.4 N·m.

Unique Aspects: 

The FBJ process affords short weld time with no pilot hole or surface preparation needed prior to joining. FBJ can perform multi-stack sheet joining, as well as weld bonding (with FBJ plus adhesive) for corrosion mitigation and increased strength.

Availability: 

The equipment is available for various partnership arrangements with industry.

Single Point of Contact: 

Name: Dr. Yong Chae Lim
Email: limy@ornl.gov
Phone: 865-574-4805

References: 
  1. Y.C. Lim, L. Squires, T.-Y. Pan, M. Miles, G.-L. Song, Y. Wang, Z. Feng, “Study of mechanical joint strength of aluminum alloy 7075-T6 and dual phase steel 980 welded by friction bit joining and weld-bonding under corrosion medium,” Materials and Design, 69 37-43, 2015.
  2. L. Squires, Y.C. Lim, M. Miles, Z. Feng, “Mechanical properties of dissimilar metal joints composed of DP 980 steel and AA 7075-T6,” Science and Technology of Welding & Joining, 20 (3) 242-248, 2015.
Supporting Document(s):