Surface Quality Control by X-Ray Fluorescence

Abstract

Elemental analysis by X-ray fluorescence, XRF, is a well-known technique, widely used in laboratories and industrial plants. XRF equipment manufacturers offer accessories and programs to integrate their equipment into automated plants and use it as quality control tools. The relationshipbetween the surface roughness of the samples and the quality of the measurement is studied and its physical principles are known. In this work it is proposed to use an XRF equipment to analyze the surface roughness of the elements produced in chain, and establish a pass/do not pass control of a batch.By integrating the XRF equipment into the chain, and comparing the measurement with a previous measurement considered reference (which can be done with other equipment such as a roughness meter or confocal microscope) it can be determined if the surface roughness of the samples conforms to the established tolerance limits. The advantages of using an XRF equipment are: using equipment that is already in the plant, automating the control process, integrating an XRF into a flexible manufacturing environment and non-contact roughness analysis (surface texture).In this work the authors start from different machined specimens of aluminium alloy perfectly known by spark emission spectrometry to the appropriate dimensions to be measured in an XRF spectrometer. The surface to be evaluated is machined until the desired order of roughness is achieved, its surface finish is determined by optical methods and subsequently measured in the XRF equipment. Different specimens, are produced to determine the changes in the XRF measurements. The intensity of selected elements in each specimen is related to the surface finish and conclusions are drawn.