Background

IncoTest combines instrumental and classical methods of chemical analysis. Providing such a wide range of techniques ensures the client that samples are analysed by the most economical method, depending on the type of material, the form of the sample and the level of accuracy required. Normally, one or more of the following methods are used for analysis of steels and nickel, cobalt, aluminium, copper and titanium-based alloys:
X-ray Fluorescence (XRF)

Simultaneous and sequential X-ray spectrometry is used for the determination of main and residual impurity elements. Accuracy is largely determined by the quality and range of Certified Reference Materials (CRMS) used for calibration. IncoTest has access to a common suite of over 1500 samples covering commercially available CRMs and in-house standards.
Optical Emission Spectrometry (OES)

This method is used by Incotest to determine trace and residual impurity elements and is particularly useful for low atomic number elements such as boron, magnesium, aluminium, phosphorous and calcium.

When coupled with a Hollow Cathode Source, OES is used to determine low boiling point elements such as lead, bismuth, silver and tellurium at very low concentrations. These elements, which can seriously impair the performance of high-temperature steels and nickel-based superalloys, are routinely determined at levels below one part per million. IncoTest uses a wide range of commercial CRMs and in-house reference materials for the determination of low boiling point elements at these levels.
Atomic Absorption Spectrometry

Residual and trace elements are analysed using Atomic Absorption and Graphite Furnace Atomisation (GFA). IncoTest's equipment employs Zeeman Background Correction to minimize interference's and improve accuracy at trace levels. This method is particularly useful where there are no CRMs available.
Gas Analysis

Incotest use the Carrier Gas Extraction methods to determine oxygen, nitrogen and hydrogen levels. The sample is melted in an inert gas stream in a graphite crucible and the gasses evolved are measured by thermal conductivity or infra-red absorption.
Carbon & Sulphur Analysis

Carbon and sulphur are determined by RF Combustion in oxygen. This results in evolution of carbon dioxide and sulphur dioxide. Their concentrations are then measured by infra-red absorption
Inductively Coupled Plasma (ICP-OES)

Incotest use This technique as an alternative to XRF and conventional OES when sample size is limited or the sample form is unsuitable (eg turnings, fine wire or powder. With ICP-OES, the sample is dissolved and aspirated in an argon plasma where it vaporizes and emits a characteristic spectrum which is analysed by OES. The analysis involves dissolution of the sample, and therefore it is relatively easy to prepare closely matching calibration standards from pure metals and compounds. This is particularly important where appropriate CRMs are not available or where an independent overcheck is needed.
Wet Chemistry

Classical chemical analysis can be used to supplement instrumental methods and is important where overcheck or referee analyses are required.