We embrace Failure Analysis because it leads to advancement in Excel’s capabilities and advancement on-site at the customer’s mine or quarry. Thanks to our in-house metallurgy lab, we can offer our expertise and lab capabilities to support your specific challenges.
Within the mining and aggregate industries we serve, metal wear and even fractures are an expected part of life in the real world. There are times when the service conditions exceed what even the finest materials can bear. Whether or not the failed part is an Excel product, we embrace opportunities to analyze these failures in our metallurgical lab because they represent opportunities to advance the art and science of producing machinery and components that do more for the customer’s bottom line. We engineer and analyze components that push out the boundaries of service life.
Only when the failure mode is fully understood, can solutions can be explored that lead to design and/or processing improvements of your nagging problems. Our in-house metallurgical lab stands ready to serve you, whether the product is from Excel or not. We have at our fingertips all of the latest tools and technologies to do the job.
Here are some types of non-destructive testing methods of failure analysis (part of forensic engineering):
Ultrasonic Inspection uses very sensitive, deep-penetrating pulse-waves that allow us to see very small and very deep flaws within a component. Any flaws present “reflect” back a signature to the original source, giving their location away. Attenuation methods may also be used, whereas the waves pass through the component to an additional sensor, rather than reflect back, revealing problems within a component as they travel.
Magnetic Particle Inspection detects surface and subsurface flaws within ferrous materials like iron. Very simply, a magnetic field is created throughout the component in question, then magnetic particles are applied to the part. If a problem exists, the particles are attracted to the problem area.
Uniaxial Tensile Testing subjects a metallic sample to a controlled tension until the sample fails. Resulting data helps us select the right material for a specific application, and also helps us find out how a new material will react to certain physical forces.
Dye Penetrant Inspection locates surface-breaking defects when hairline fractures invisible to the naked eye, for example, take on the colored dye applied to the surface of the component. When the excess dye is removed and a developer is applied, the fracture reveals itself.
Radiographic Testing uses short wave electromagnetic radiation to “see inside” a component. X-ray machines are commonly used in this application to visually detect subsurface flaws.
Remote Visual Inspection incorporates the use of video borescopes, cameras, and even robotics in some cases. “RVI” is a viable alternative for gathering visual data when it is not physically possible for a human to enter the inspection area, or if there is a deficiency in light levels, etc.
Metallography is the study of physical structure and components of metals, typically using microscopy. A sample of the component’s surface is ground, polished, and/or etched in preparation for viewing. Then the sample is analyzed using common optical microscopes. However, in extreme cases, an electron microscope can be necessary.
Eddy-Current Testing uses electromagnetic induction to find flaws within a component. A circular coil carrying current is placed within proximity to the component. Alternating current in the coil generates a changing magnetic field through the component and generates eddy-current. Variations in this current can be interpreted to locate flaws within the component. This testing method is especially helpful when testing components with complex geometries.
Low Coherence Interferometry is a non-contact optical sensing technology. An optical probe directs a low-coherence light beam at a sample surface and sends reflected light signals back to the interferometer. The reflected optical data from each single scan point is interpreted by the interferometer as an interference pattern and recorded as a depth profile (A-Scan). By scanning the probe in a linear fashion across the sample, a cross-section (B-scan) is obtained. 3D volumetric images can be generated by combining multiple cross-sections.
Hardness Testing measures how resistant solid matter is to various kinds of permanent shape change with application of force. Scratch hardness measures resistance to fracture or permanent plastic deformation. Indentation hardness measures resistance to deformation from a constant compression load from a sharp object. Rebound hardness measures the height of the “bounce” of a diamond-tipped hammer dropped onto the component from a fixed height.
Charpy Impact Testing determines the amount of energy absorbed by a material during fracture. The quantitative results will measure the toughness of the component, while the qualitative results will measure the ductility of the component.