Preparation and Certification
Standards are prepared in the form of 64mm diameter, circular disks. Thickness is approximately 25mm, with the few exceptions indicated in the catalog listings. All standards are stenciled to show the catalog number, production lot and section number. The metallurgical structure is controlled to produce ablation and excitation similar to that of chill-cast disks when used according to the methods cited. The certified compositions are determined using two or more independent analytical methods which may include wet chemical analysis, inductively-coupled plasma spectrometry, X-ray fluorescence, point-to-plane spark excitation, glow discharge mass spectrometry or other approaches deemed appropriate for a specific application.
All standards are evaluated for uniformity both within and among sections by extensive spectrochemical testing. The composition is measured by comparison with Alcoa master standards. Extensive statistical analysis is used to ensure the accuracy of the final composition certification, the chemical and physical uniformity, and that the performance of the standards is fit for use.
The process flow chart below shows the progression of an order from the time the sales administrator recieves it until it is shipped to the customer.