کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1603825 | 1515989 | 2012 | 7 صفحه PDF | دانلود رایگان |
Tungsten powder (0.6–0.9 μm) was sintered by field assisted sintering technology (FAST) at various processing conditions. The sample sintered with in-situ hydrogen reduction pretreatment and pulsed electric current during heating showed the lowest amount of oxygen. The maximum relative density achieved was 98.5%, which is from the sample sintered at 2000 °C, 85 MPa for 30 min. However, the corresponding sintered grain size was 22.2 μm. To minimize grain growth, nano tungsten carbide powder (0.1–0.2 μm) was used as sintering additive. By mixing 5 and 10 vol.% WC with W powder, densification was enhanced and finer grain size was obtained. Relative density above 99% with grain size around 3 μm was achieved in W–10 vol.% WC sintered at 1700 °C, 85 MPa, for 5 min.
► W powder (0.6-0.9 µm) sintered by FAST (2000oC, 85 MPa, for 30 min) was ~99% dense.
► Excessive grain growth could not be avoided and the final grain size was 22 µm.
► WC additive(10 vol.%) allowed >99% density even at 1800oC, 85 MPa, for 5 min.
► The grain size of the material was reduced to 3 µm (86% reduction).
► The hardness was increased from 35 HRC in pure W to 50 HRC in W-10 vol.%WC.
Journal: International Journal of Refractory Metals and Hard Materials - Volume 31, March 2012, Pages 114–120