Removal of Ni-Activator from the Activated Sintered W-Compact by High Vacuum Treatment
A small amount of nickel added to W-powder as an activator can increase greatly the sinterability of the W-powder compact, enabling full densification to be achieved at the relatively low sintering temperature of about 1200ºC–1400ºC. However, the presence of Ni-activator causes a negative effect on the mechanical properties of the activatedly sintered W-parts, resulting in extreme brittleness associated with a brittle Ni-rich phase. Therefore, Ni-activated sintered W-compacts can not be subjected to further plastic working process for a final shaping.1 If after playing a positive role as an activator in the first stage of sintering,the Ni-activator can be removed fully or partly from the activated sintered W-compact, the degree of detrimental effect might be substantially reduced.
KeywordsEvaporation Rate Initial Porosity Reference Specimen Weight Loss Rate Sintered Compact
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