SwRI: Failure Prevention of Structural Components: isolates the causes of catastrophic failure of components from compressors, diesel engines, aircraft, heat exchangers, pressure vessels, piping, medical devices, etc.

	Drawing on experience from past projects, multidisciplinary resources, and client input, SwRI staff members collaborate to determine failure mechanisms and root causes, such as on the fracture surface of this failed drive shaft.

Using systematic failure analysis, Southwest Research Institute (SwRI) isolates the causes of catastrophic failure of components such as compressor components, diesel engine components, aircraft structures, heat exchangers, pressure vessels, piping, and medical devices. Because SwRI neither manufactures nor endorses industrial products, investigations are impartial and unbiased, and client confidentiality is protected.

Failure Prevention

Failure investigations help clients prevent failures, extend component service life, and establish inspection intervals. SwRI conducts analyses to:

• Determine the causes of failure

• Identify design and operating deficiencies

• Improve reliability and safety

• Lower operating costs

• Provide impartial evaluations

SwRI engineers often identify corrosion mechanisms and fatigue when conducting metallurgical failure analysis. The photomicrograph above left shows branched intergranular cracking and selective phase attack in a nickel-aluminum-bronze flange fitting from an offshore platform firewater system. The SEM fractograph on the right shows fatigue striations observed on a 7075 aluminum airframe component.

Primary Failure Analysis

SwRI engineers have extensive experience in identifying failure mechanisms including:

• High- and low-cycle fatigue

• Stress corrosion cracking

• High-temperature degradation

• Brittle failure mechanisms

• Fretting and wear mechanisms

• Welding defects

• Petrochemical corrosion mechanisms

Failure Prevention Facilities and Equipment

	Using a scanning electron microscope equipped with a servo-hydraulic loading stage, SwRI can perform controlled crack growth studies at high magnifications, as well as determine fracture morphologies and microstructural anomalies of failed components.

SwRI's mechanical engineering laboratories include:

• Three scanning electron microscope (SEM) systems for fractographic and metallographic analysis

• Servo-hydraulic loading stage for SEM to enable in-situ analysis of controlled fractures under high magnifications

• Powder X-ray diffractometer for crystallographic analysis of materials and deposit analysis

• Two profilometers for surface roughness measurements

• Three energy-dispersive X-ray spectrometer (EDS) systems, coupled to each SEM, to identify elemental composition of materials, such as aggressive corrosion products

• Scanning auger microprobe spectrometer to identify elemental composition of contaminants and microstructural phases

• Scanning-tunneling and atomic force microscopes (STM/AFM) for analysis of nanoscale surface topography

• Metallographs for heat treat verification, microstructural examination, and material characterization

• Portable microscope, hardness testing unit, and replication kit for field investigations

• Fully equipped mechanical testing laboratory, including 40 closed-loop, servo-hydraulically controlled mechanical test systems

• Autoclaves for high-pressure and high-temperature corrosion investigations

• Fourier transform infrared (FTIR) spectrophotometer for molecular-level compositional analysis of non-metallics

• Raman spectroscopic imaging and microanalysis system for spatially mapped compositional analysis of various materials

• HEPA filtrated metals lab and hot cells capable of handling multicurie specimens

Additional Failure Analysis Services

When investigations require in-depth studies of failure mechanisms, SwRI applies:

• Finite element analysis

• Damage tolerance analysis

• Life extension predictions

• Mechanical testing

• In-service condition assessment

• Nondestructive evaluation

• Maintenance optimization

• Design or redesign

For more information about failure prevention of structural components capabilities at SwRI or how you can contract with SwRI, please contact Paul E. Redmond at predmond@swri.org or  (210) 522-3163.