Practical Failure Analysis

, Volume 1, Issue 2, pp 55–58 | Cite as

Failure analysis of a polysulfone flow sensor body — A case study

  • Jeffrey A. Jansen
Peer Reviewed Articles
  • 64 Downloads

Abstract

A failure analysis was conducted on a flow-sensing device that had cracked while in service. The polysulfone sensor body cracked radially, adjacent to a molded-in steel insert. This article describes the investigative methods used to conduct the failure analysis. The techniques utilized included scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermomechanical analysis, and melt flow rate determination. It was the conclusion of the investigation that the part failed via brittle fracture, with evidence also indicating low cycle fatigue associated with cyclic temperature changes from normal service. The design of the part and the material selection were significant contributing factors because of stresses induced during molding, physical aging of the amorphous polysulfone resin, and the substantial differential in coefficients of thermal expansion between the polysulfone and the mating steel insert.

Keywords

coefficient of thermal expansion failure analysis insert molding plastic polysulfone 

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References

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    James E. Harris:Handbook of Plastic Materials and Technology, Irvin I. Rubin, ed., John Wiley & Sons, Inc., New York, NY, 1990, pp. 487–491.Google Scholar
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    James E. Harris:Handbook of Plastic Materials and Technology, Irvin I. Rubin, ed., John Wiley & Sons, Inc., New York, NY, 1990, p. 488.Google Scholar

Copyright information

© ASM International - The Materials Information Society 2001

Authors and Affiliations

  • Jeffrey A. Jansen
    • 1
  1. 1.Stork Technimet, Inc.New Berlin

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