Use of Ti in hard metal alloys – Part I: structural and microstructural analysis

Abstract

Nanosized WC, and binders Co, Ti and Ti-Co, are used to process hardmetals. Titanium (Ti) was proposed to reduce and even replace the Co in these composites, verifying the effectiveness of the new binders. Samples of nanosized WC with 10 wt% Co, 9 wt% WC 1 wt% Ti -Co, WC-10 wt% Ti were cold compacted at 200 MPa and sintered at 1500 8C during 1 hour under vacuum of 10 -2 mbar for the processing of hardmetal were performed. The structural characterization by X-ray diffraction and microstructure by scanning electron microscopy (SEM) and EDS microanalysis of the sintered material. We observed the presence of the W 2 C phase in the sintered samples, and Co 3 W phases in the samples with Co content and a good distribution of binder phase, leading to formation of small "pool" of Co and Ti and small porosity and well distributed. It was proved that using Ti as binder phase, the neta phase formation was avoided.

Manufacturing of Novel Nanostructured TiCrC Carbides Using Mechanical Alloying and Spark Plasma Sintering

“…The fabricated composites obtained from mixtures containing 50 wt.% Cu and 30 wt.% Cu showed a Vickers hardness of 490 ± 50 HV1 and 715 ± 55 HV1, respectively. Lamim et al [18] revealed that WC-Ti sintered by SPS at 1500 • C for 1 h presents three phases (W 2 C, TiC, and (W 1−x Ti x )C), and interesting mechanical properties, such as hardness (1575 HV30) and fracture toughness (11.05 MPa.m 1/2 ). Similarly, Ouar et al [19] have investigated the magnetic and mechanical properties of Co 80 Ni 20 nanopowders prepared by using a polyol process and then being consolidated by using SPS at 500 and 600 • C for 5 min and under a pressure of 100 MPa.…”