Description:
<jats:title>Abstract</jats:title><jats:p>Industrial tungsten wires were fractured using Auger equipment. The concentration of potassium on the fracture surface of the variously heat‐treated wires was markedly different. The results can be explained assuming that the wires were fractured along the potassium second phases. The spectra, similar to those normally interpreted as indicative of monolayer potassium segregation on the fracture surfaces, are here interpreted as arising from diffusion across the surface after fracture from the potassium inclusions and not from a segregated layer.</jats:p>