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Measurement of particle size and internal strain in doped tungsten powder by X‐ray methods
Author(s) -
Salewski W.
Publication year - 1987
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170220424
Subject(s) - tungsten , materials science , sintering , doping , incandescent light bulb , particle (ecology) , particle size , fabrication , metallurgy , metal , potassium , strain (injury) , tungsten carbide , composite material , chemical engineering , optoelectronics , optics , medicine , oceanography , physics , alternative medicine , engineering , pathology , geology
In the powder metallurgical process of tungsten wire fabrication for incandescent lamps the stepwise reduction of tungsten oxides (WO 3 or W 20 O 58 ) plays an important role in respect to the efficiency of doping elements (especially potassium) for the formation of the non sag structure of tungsten wires. The influence of temperature and time in the reduction steps has been investigated by means of the X‐ray method for determination of particle size and internal strain described by KOCHENDOERFER. It has been founded a close relationship between the internal structure of metal powder (especially internal strain) and the potassium content as well as the sintering behaviour of these powders. – The KOCHENDOERFER method is a usefull tool for the improvement of reduction parameters in regard to the sintering behaviour.