Sintering and microstructural development in WC/Co-based alloys made with superfine WC powder

Fabrication of ultrafine and nanocrystalline WC–Co mixtures by planetary milling and subsequent consolidations

“…Looking for higher mechanical properties and the needed of smaller and higher precision tooling has led to the use of finer powders, being classified as submicrometric (,0?6 mm) and ultrafine (,0?3 mm) which have showed their excellent potential of improvement. [6][7][8] In this way, after being used for specific tooling in the wood and electronic industry the uses have extended to cutting tools for other materials (ferrous, non-ferrous, plastics) and industries (general machining, mining, casting, etc). 9,10 Powder size reduction to nanometric scale and development of nanostructured coatings and bulk materials are nowadays an important subject of research and have emerged as very promising materials.…”

Fabrication of full density near-nanostructured cemented carbides by combination of VC/Cr3C2 addition and consolidation by SPS and HIP technologies

“…The consolidation of nanostructured WC-Co powder has been studied using a variety of techniques including the standard liquid phase sintering (LPS) [4][5][6][7][8][9], hot isostatic pressing (HIP) [10], unconventional processes such as microwave sintering [11,12] and spark plasma sintering (SPS) [13][14][15][16][17][18], high frequency induction-heated sintering (HFIHS) [19][20][21], rapid omni compaction (ROC) [22], pulse plasma sintering (PPS) [23] and ultrahigh pressure rapid hot consolidation (UPRC) [24]. Due to the high temperature during sintering, grain growth occurs very quickly and it explains that the finest average grain sizes of sintered WC-Co reported in the literature up to date, using nanograined powders, is around 200-300 nm.…”

“…Vanadium carbide (VC) and chromium carbide (Cr 3 C 2 ) are the most effective grain growth inhibitors for this system thanks to their high solubility and mobility in cobalt phase at low temperatures [25][26][27].…”

Microstructural control of ultrafine and nanocrystalline WC–12Co–VC/Cr3C2 mixture by spark plasma sintering

“…To control the grain growth in ultrafine WC-Co composites, one of the keys is a suitable selection of the second-phase additives as grain growth inhibitors. By far vanadium carbide (VC) and chromium carbide (Cr3C2) are the most effective grain growth inhibitors due to their high solubility and mobility in cobalt phase at lower temperatures [6][7][8]. In addition, the grain growth can be inhibited to a certain extent by using special sintering technologies to accelerate the heating rate, increase the densification rate, decrease the sintering temperature and shorten the holding time, such as microwave sintering [9], rapid hot pressing sintering [10,11], spark plasma sintering (SPS) [12], and so on.…”