Metallurgical Analysis with the Phenom Desktop SEM

The morphology, composition, and distribution of key microstructural features of many engineering materials influence their properties. Although conventional optical microscopy can be used to observe these features, a scanning electron microscope (SEM) is ideal in cases requiring higher magnification and 3D detail.

Phenom Desktop SEM

The Phenom™ desktop SEM has a higher resolution of 30nm compared to the resolution limit of optical microscopes of 200nm. It is economical, rapid, and convenient to operate when compared to a conventional SEM. The Phenom can be used to perform rapid analysis of common engineering alloys in areas, including research studies, failure analysis, quality control, and routine metallurgical analysis.

Advantages of Phenom Desktop SEM

Metallography provides data about alloys relating their composition and processing to their properties and performance. For instance, the yield strength of titanium alloys has been related to the thickness of the α-laths.

Accurate measurement of the α -laths provides key input for emerging models that can deduce alloy properties. The α-laths (darker phase) as well as the β-ribs (lighter phase) between the laths of β-processed Ti-6-4 are delineated in Figure 1.

BSE Mode of ß-processed Ti-6-4

Figure 1. BSE Mode of ß-processed Ti-6-4

The average thickness of these laths can be calculated using proven measuring methods with an uncertainty of roughly 50-100nm, which is lower than the resolution limit of traditional optical microscopes of 200nm.

Figure 2 shows sub-micron sized α-laths formed in titanium alloys due to a second nucleation event. This phenomenon can often reinforce the alloy. Conventional optical microscopes find it difficult to image such fine features, or even to confirm their existence. The Phenom™ desktop SEM can readily observe these features.

BSE Mode of β-processed Ti-6-4

Figure 2. BSE Mode of β-processed Ti-6-4

Figures 3 and 4 depict additional microstructural features of a cast aluminum alloy, revealing the impact of shrinkage porosity and size and distribution of the intermetallic phases (lighter phases) on the alloy properties.

Figure 3 demonstrates the ability of the Phenom to acquire topological data such as shrinkage porosity details owing to its intrinsic depth of focus as well as the simultaneous acquisition of data on the distribution of phases within the microstructure represented by contrast variations in the image.

Intermetallics and porosity of an automotive Al alloy

Figure 3. Intermetallics and porosity of an automotive Al alloy

Intermetallics of an automotive Al alloy

Figure 4. Intermetallics of an automotive Al alloy

Figures 5 and 6 illustrate Ni-based superalloys, which are advanced alloys and the product of decades of intense research. The alloy is composed of a disordered gamma matrix and ordered gamma-prime, providing it a unique combination of strength and creep resistance.

This very attractive combination makes it a suitable material for certain regions of gas turbine engines, for instance jet engine. Al typically contains high level of gamma prime, represented in a darker shade in BSE mode as illustrated in Figure 6.

Nickel-base superalloy

Figure 5. Nickel-base superalloy

Nickel-base superalloy

Figure 6. Nickel-base superalloy

About Phenom-World

Phenom™, world’s fastest Desktop Scanning Electron Microscope takes your imaging performance to a higher level. The Phenom desktop scanning electron microscope (SEM) helps customers stay competitive in a world where critical dimensions are continuously getting smaller.

The Phenom desktop SEM combines superb imaging power up to 100,000x and outstanding technical performance with better depth of focus and chemical contrast. It is the smart, affordable and market’s fastest solution that enables engineers, technicians, researchers and educational professionals to investigate micron and submicron structures.

With the Phenom proX we offer integrated, powerful EDS microanalysis to complete the optical performance of our SEM-range. Any Phenom system can be tailored to suit application and sample needs by choosing one of the many Pro Suite-based software solutions or specially designed hardware accessories.

Phenom-World helps you to stay competitive in a world where critical dimensions are continuously getting smaller. The Phenom desktop SEM offers direct access to the high-resolution and high-quality imaging necessary in a large variety of applications. It is an affordable solution that enables engineers, technicians, researchers and educational professionals to visualize micron and submicron structures.

This information has been sourced, reviewed and adapted from materials provided by Phenom-World BV.

For more information on this source, please visit Phenom-World BV.

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