Recrystallization and composition dependent thermal fatigue response of different tungsten grades

Industrial pure tungsten grades, manufactured by using a variety of manufactured techniques, are available worldwide in many different types of semifinished products, i.e. rods, wires, ribbons, and sheets. Thereby, the recrystallization temperature varies depending on the applied degree of deformation but also depending on the materials composition, i.e. the materials purity and in particular the level of certain impurities. In order to compare different available industrial tungsten grades and a newly developed PIM-W grade, on the one hand recrystallization studies at three different temperatures from 1573 to 2073 K for 1 h were performed using microstructural analyses and Vickers hardness testing. On the other hand, the thermal shock induced low cycle thermal fatigue response of the material in its different recrystallization stages was done using high heat flux tests at 1273 K base temperature, applying 1000 shots with 1 ms and 0.38 GW/m2 and post-mortem characterization, i.e. profilometry and metallography. The obtained results are related to the microstructural and mechanical features of the materials as well as the chemical composition of the individual tungsten grades.