Low Plasticity Burnishing

 

Figure 1

M-Series Neck Fatigue Chart

Low Plasticity Burnishing, or LPB, is a patented process created by Lambda Technologies of Cincinnati, Ohio, and was originally utilized to treat turbine blades on aircraft engines. The LPB process imparts residual compressive stresses to the surfaces of metal parts, thus dramatically enhancing the fatigue strength. The stress levels are optimized for a particular part by controlling the normal force applied to the spherical tool, which rolls over the part surface (Figure 1). Furthermore, parts treated with LPB have a polished appearance, which reduces the incidence of fretting and surface defects that can lead to crack initiation.

  • LPB is a process that treats the taper junction area to reduce the incidence of wear, fretting and fracture of the metal.
  • LPB is applied in a helical pattern around the distal neck taper of the AcuMatch® M-Series. This pattern creates a compressive stress field on the entire taper surface.
  • One important feature of the LPB application method is that it is highly controllable and can be validated, which ensures that the process can be successfully applied to every part.
  • The LPB process greatly improves the performance of the taper junction in the AcuMatch M-Series.
  • Fatigue strength of the AcuMatch M-Series neck segment was 1050 lbs at 10 million cycles prior to application of the LPB process. After the LPB process was applied, the fatigue strength increased 33 percent to 1400 lbs at 10 million cycles.