{"id":12521,"date":"2024-08-07T20:50:59","date_gmt":"2024-08-07T20:50:59","guid":{"rendered":"https:\/\/www.thermofisher.com\/blog\/metals\/?p=12521"},"modified":"2025-08-18T14:04:05","modified_gmt":"2025-08-18T14:04:05","slug":"exploring-edxrf-analysis-for-cast-iron-composition","status":"publish","type":"post","link":"https:\/\/www.thermofisher.com\/blog\/metals\/exploring-edxrf-analysis-for-cast-iron-composition\/","title":{"rendered":"Exploring EDXRF Analysis for Cast Iron Composition"},"content":{"rendered":"

In the field of material analysis, Energy Dispersive X-ray Fluorescence (EDXRF) spectrometry has emerged as a powerful technique for determining the elemental composition of various materials, including metal alloys<\/a> \u2013 specifically for this blog article, cast iron compositions.<\/p>\n

Understanding Cast Iron<\/h2>\n

Cast iron is a widely used material known for its excellent mechanical properties, high wear resistance, and good castability. It is composed primarily of iron (Fe) along with varying amounts of carbon (C), silicon (Si), and other alloying elements — noted below.<\/p>\n

The US Metal Casting sector, according to the US EPA<\/a> website, includes \u201cestablishments that pour molten ferrous metals (iron and steel) or nonferrous metals under high pressure into molds to manufacture castings. Ferrous metal casting includes those castings made with grey iron, ductile iron, malleable iron, and steel. Nonferrous castings are predominantly aluminum but might also be brass, bronze, zinc, magnesium, and titanium.\u201d<\/p>\n

The EPA also notes that the United States is the largest producer of cast products in the world and that more than 90 percent of all manufactured goods in the United States contain cast metal components \u2013 which can be found in the mining, metallurgical, and automotive industries, in various types of machinery, pipes and plumbing fixtures, boilers, construction, and even in kitchenware. Cast iron skillets are familiar to many chefs and home cooks because they appreciate the pan\u2019s ability to sear food and retain heat better than aluminum cookware.<\/p>\n

The Right Ingredients<\/h2>\n

It is crucial to the quality of the finished product that the cast iron is made to specification. Pipes could crack, bridges and buildings could collapse, and vehicles could fail if the alloy is not made correctly. The US GSA<\/a> provides general information about cast iron and a set of guidelines.\u00a0 The GSA website notes that cast iron is \u201cprimarily composed of iron (Fe), carbon (C) and silicon (Si), but may also contain traces of sulphur (S), manganese (Mn) and phosphorus (P). It has a relatively high carbon content of 2% to 5%. It is hard, brittle, nonmalleable (i.e. it cannot be bent, stretched, or hammered into shape) and more fusible than steel. Its structure is crystalline, and it fractures under excessive tensile loading with little prior distortion. Cast iron is, however, very good in compression. The composition of cast iron and the method of manufacture are critical in determining its characteristics.\u201d<\/p>\n

I\u2019ll repeat that:\u00a0 The composition of the cast iron is critical.<\/p>\n

EDXRF spectrometry can help ensure that the composition meets specifications.<\/p>\n

EDXRF Spectrometry<\/h2>\n

In the characterization of iron alloys, combustion analysis with infrared spectroscopy is currently the reference technique for the determination of carbon content. Recent improvements in detector windows, however, have also enabled carbon analysis with energy-dispersive X-ray fluorescence<\/a> (EDXRF).<\/p>\n

EDXRF is a non-destructive analytical technique that utilizes the characteristic X-rays emitted by a sample when exposed to high-energy X-ray radiation. The emitted X-rays are specific to the elements present in the sample, allowing for their identification and quantification. In the context of cast iron analysis, EDXRF offers several advantages, including rapid analysis, minimal sample preparation, and the ability to measure both major and trace elements.<\/p>\n

Experimenting with EDXRF and Cast Iron<\/h2>\n

We tested an EDXRF Spectrometer<\/a> to see if it was appropriate for cast iron composition analysis. It was equipped with a 50-W, 50-kV rhodium (Rh) anode X-ray tube, a filter wheel with 9 selectable filter positions, and a state-of-the-art silicon drift detector (SDD500G) fitted with a 0.9-\u00b5m thick graphene window. This window is highly transparent to low-energy X-rays, like those emitted by carbon atoms, and allows for the detection of all elements in the periodic table from carbon (Z = 6) to americium (Z = 95). Additionally, it offered a sample spinner, a 10- or 20-position sample changer, and the ability to analyze in either air, helium, or vacuum. Eight VASKUT cast iron certified reference materials (CRMs) were used to set up calibration curves.<\/p>\n

Light elements, including carbon, were measured using the Low Za condition, with an excitation voltage of 4 kV and no primary beam filter. To generate enough carbon intensity, a 600 s live time was used for the calibration. Heavier elements were measured with a second condition (Mid Za) which has an excitation voltage of 16 kV and uses a thin Pd primary beam filter. A 120\u00a0s measurement live time was used for this condition. All measurements were conducted in vacuum, which is mandatory for the detection of carbon X-ray fluorescence and generally improves sensitivity for light elements.<\/p>\n

Results and Discussion<\/h2>\n

It was demonstrated that an EDXRF spectrometer<\/a> can quantify a range of elements in cast iron, including C, Si, P, S, Cr, Mn, and Ni. Simple calibration curves, requiring few matrix corrections, were easily generated for all elements. Repeatability data shows excellent accuracy and precision, even at short measurement times. These results highlight the applicability of EDXRF for the determination of cast iron composition.<\/p>\n

You can read additional details, including information about instruments used, measurement conditions, spectra generated, calibration results, and repeatability tables in the application note EDXRF analysis of cast iron composition with ARL QUANT\u2019X Spectrometer<\/em><\/a><\/p>\n

Resources<\/h2>\n