Need technical help with a metals or materials problem ? Amenex can find out what needs to be changed or improved in order to solve your problem.

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What Amenex does:

Amenex is an independent, privately owned metals and materials consulting firm specializing in the analysis of materials problems.

We provide technical expertise and assistance to law firms, insurance companies, testing laboratories, manufacturers, power companies, and government agencies.

We presently partner with area metallurgical laboratories in order to obtain many of the services described herein.  Nevertheless, we are retaining the descriptions of the machines and instruments that we once used every day, so that you can see what is involved in the investigation of metallurgical problems. See this list of former and surplus Amenex resources.

I.   We were asked by a manufacturer to determine why the blades of large aluminum ventilation fans were breaking in service. Through metallography, mechanical analysis, and vibration testing, we showed that poor casting quality coupled with vibration and restricted air flow were the causes of these failures. We recommended adjusting the speed of the fans to avoid resonant frequencies and to take steps to prevent stalling of the airflow across the blades.

II.  A large chemical processing plant was encountering troublesome leaks in stainless steel heating coils. Through in-situ metallography and replication, we found that the leaks were the result of chloride stress-corrosion cracking. This client now avoids chlorides in the heat-transfer fluid and in the external insulation material, thereby eliminating this costly problem.

III. A law firm asked us to investigate the failure of a fractured shotgun receiver which resulted in serious injury. Through scanning electron microscopy of the two fracture surfaces (both direct and by two-stage replicas) we concluded that the frame of the receiver was overloaded by stress concentrations and poor design, then damaged during machining with a dull cutter.

IV. A pulp & paper manufacturing company contracted with Amenex for a corrosion study and for help with selection of alloys resistant to pitting and stress corrosion cracking, for use in a multi-million-dollar demonstration plant. Through periodic testing of corrosion coupons and cross-sections cut from the existing pilot plant, we located the most severe environment in the process, made the necessary evaluations, and recommended to this client the appropriate corrosion-resistant alloys.

V.  A law firm needed to discover why the lid of a car crusher failed, resulting in the death of a worker. Through scanning electron microscopy, metallographic testing, and mechanical analysis of the various frame members, we reported that the cause of this catastrophic failure was lack-of-fusion defects in key welds, not misuse of the equipment by the owner or operators.

VI. A manufacturer asked Amenex to investigate the cracking of a flange in a large reaction vessel. Our analysis indicated that a combination of thermal stress, caustic embrittlement, brittle crack growth, and ductile crack arrest were contributing factors. Scanning electron fractography enabled us to count the number of complete crack growth cycles, which was then related to the number of shut-downs and re-starts during the manufacturer's process. We suggested a method for monitoring thermal stress during startups to minimize further crack growth.

VII. A cookie manufacturer needed help to determine the sources of ferrous debris collected by a magnet from their incoming raw materials. Through scanning electron microscopy and metallography on the tiny fragments, we were able to identify the origins and compositions of the particles, and thereby which vendors were lax in their refining processes. Our client was able to mandate stringent quality control measures based on our findings to eliminate this problem.

VIII. One of a pair of high-pressure steam headers cracked at the socket welds while it was being stress relieved, whereas its mate exhibited no such failures.  Fortunately the fabricator had saved rings of the original header material, and creep-rupture testing of specimens from each ring revealed that the defective header was much stronger than its mate and so probably had not been normalized at the steel plant.  Presumably the mate received a double treatment !  The cause of the cracking of the defective header was therefore attributed to stress-relief cracking, which occurs when certain steels are exposed to high temperatures under excessive stress.

IX.  Solder joints were inexplicably failing in a rubber-encapsulated aircraft instrument.  We examined the fracture surfaces and microstructure of the solder and discovered that the failure mechanism was creep rupture, which occurred while the encapsulant was being cured, because the rubber expanded with heat and forced its way past the soldered parts as it moved towards the one pressure-relief opening.