초록 ▼

It has been discovered that potassium retention in NS tungsten processing may be improved by double doping tungsten blue oxide (TBO) prior to reduction. The novel `double-doping` process consists of dry doping standard singly doped K--Al--Si TBO with potassium nitrate, KNO.sub.3, followed by the sta

It has been discovered that potassium retention in NS tungsten processing may be improved by double doping tungsten blue oxide (TBO) prior to reduction. The novel `double-doping` process consists of dry doping standard singly doped K--Al--Si TBO with potassium nitrate, KNO.sub.3, followed by the standard reduction, acid washing, sintering, rolling and drawing steps. In another aspect, the novel method includes an aqueous extraction of heteropolytungstate anion [SiW.sub.11 O.sub.39 ].sup.8- from a sample of the singly doped tungsten blue oxide to predict potassium retention.

대표청구항 ▼

[ We claim:] [1.] A method of making non-sag tungsten wire comprising the steps of:(a) wet doping tungsten blue oxide with an aqueous solution containing potassium, silicon and aluminum and drying to form a singly doped tungsten blue oxide;(b) dry doping the singly doped tungsten blue oxide with an

[ We claim:] [1.] A method of making non-sag tungsten wire comprising the steps of:(a) wet doping tungsten blue oxide with an aqueous solution containing potassium, silicon and aluminum and drying to form a singly doped tungsten blue oxide;(b) dry doping the singly doped tungsten blue oxide with an amount of potassium nitrate to form a double doped tungsten blue oxide;(c) reducing the double doped tungsten blue oxide to form a potassium-doped tungsten metal powder;(d) acid washing the potassium-doped tungsten powder;(e) pressing and sintering the potassium-doped tungsten metal powder to form an ingot; and(f) mechanically working the ingot to form a non-sag tungsten wire having an increased potassium retention compared to the same non-sag tungsten wire produced without the dry doping step (b).