Parametric analysis of interfacial stress concentrations in porous coated implants

✍ Scribed by Debra Wolfarth; Mark Filiaggi; Paul Ducheyne

• Publisher: Wiley (John Wiley & Sons)
• Year: 1990
• Tongue: English
• Weight: 630 KB
• Volume: 1
• Category: Article
• ISSN: 1045-4861
• DOI: 10.1002/jab.770010103

✦ Synopsis

Porous coated Ti-6AI-4V has a high-cycle fatigue strength that is approximately one-third the strength of the uncoated material. Stress concentrations at the interface between the porous coating and the substrate contribute to this fatigue strength reduction. Modification of the interfacial geometry may reduce the severity of the stress concentrations. The interface between the porous coating and substrate was modeled using two-dimensional finite element analysis. This analysis identified geometric parameters that affect the value of the stress concentration factor, Kt. The effect of five geometric parameters on K , was determined: contact area between porous coating and substrate (CA), sinterneck radius (r), porous coating particle radius (R), interparticle distance ( d ) , and interparticle sintering. Increased contact areas, decreased sinterneck radii, and decreased interparticle distances increased K,, while porous coating particle size had a small effect on Kt. Sintering between neighboring porous coating particles increased K , at the outermost sinternecks, but decreased K, at inner sinternecks. The results can help predict how varying these coating parameters can reduce stress concentrations in a porous coated material.