Structure and mechanical properties of TiB2/TiC – Ni composites fabricated by pulse plasma sintering method

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 29; no. 8; pp. 1795 - 1803
• Main Authors: Cymerman, K., Oleszak, D., Rosinski, M., Michalski, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2018
• Subjects: Pulse plasma sintering; Sintering; TiB2/TiC – Ni composites; TiB2/TiC – Ni composites; Pulse plasma sintering; Sintering
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2018.04.015

[Display omitted] •TiB2/TiC – Ni composites have been successfully fabricated by PPS.•The composites revealed the density above 99% and high hardness of 2400HV.•Due to double-step sintering process sintering temperature was as low as 1100 °C.•Undesirable phases like Ni3B or graphite has been avoided. TiB2/TiC – Ni composites were synthesized starting from the powders of Ti, B4C and Ni, using Pulse Plasma Sintering (PPS) method. Typically used one-step (1100 °C–10 min.) and novel double-step sintering processes (900 °C–10 min. +1100 °C–5 min.) were applied and compared. XRD studies showed that the composite obtained by double-step sintering consisted of TiB2, TiC and Ni phases. For one-step processing additionally undesired Ni3B and graphite were detected. SEM observations revealed dark-grey grains of TiB2, light-grey grains of TiC (both around 25 µm in size) and Ni areas surrounded by TiC. The composites synthesized in one- and double-step processes revealed the hardness and relative density of 2335 HV5 (±110) and 97.8% and 2470 HV5 (±70) and 99.8%, respectively. Novel double-step sintering process allowed to avoid undesired phases (graphite, Ni3B) and only TiB2, TiC and Ni were present in the structure. Additionally it was possible to decrease the temperature of the process comparing to other fabrication methods.