Activation Pretreatment of W-1.5wt%TiC Composite Powder and Its Sintering Behavior

Abstract:

Tungsten (W) powder was subjected to chemical activation pretreatment by immersion into an aqueous solution of hydrofluoric acid and ammonium fluoride, and then was reinforced with an ultrasonic wave at room temperature to obtain uniform distribution of defects (adsorbate island or steps, etc.) on the surface of W and TiC powder, increasing the surface activity of powder. W-1.5wt% TiC composites were prepared by a powder metallurgy method. A field emission electron microscope was employed to observe the surface topography of the original and chemically pretreated powder and fracture morphologies of W-1.5wt%TiC composites, and the sintering mechanism was discussed. The results show that under the condition of the same sintering process, the W-1.5wt%TiC composites after activation treatment of sintered powder achieve a relative density 7% higher than that of the original powder and more compact organization