100years of doped tungsten wire

Effect of potassium doping on the thermal shock behavior of tungsten

“…According to previous studies [26,44,45], the size distribution of potassium bubbles is crucial and should not surpass a critical size since it controls grain structure, sag resistance and high temperature strength of W-K wire. Since the typical size of potassium bubbles after sintering is some tenths of micron [46], the critical step to reduce bubble size to nanometer level (5-50 nm [27])…”

“…The potassium bubbles interact with all lattice defects and act as pinning points for dislocations as well as subgrain and grain boundary migration [15,26]. As known, potassium bubbles form the strongest high-temperature barriers compared to refractory carbides or oxides [27]. Therefore W-K is deemed an attractive potential PFM for future fusion reactors and considered as one of two most promising W-based alloys for divertor in DEMO [28].…”

History of Hardmetals

“…The development of the latter was largely solved by the respective work of Coolidge at General Electric (Schade, 2010b). The study group for electrical lighting was also in search of a proper material to substitute diamond as drawing die for NS-W after the First World War.…”

Incandescent lighting and powder metallurgical manufacturing of tungsten wire

“…The ''dope'' procedure was an accidental discovery by Aladar Pacz, back in 1922 [14]. The understanding of the role of the key element potassium was possible only since the 1960s with the help of modern analytical tools like the scanning electron microscope (SEM), the transmission electron microscope (TEM), and the Auger electron spectroscopy (AES) [15][16][17][18][19][20].…”