High-strength non-firing ceramics by mechanochemical treatment

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Japan, 2020-12, Vol.31 (12), p.4672-4678
• Main Authors: Razavi-Khosroshahi (Sena), Hadi, Ishida, Hajime, Fuji, Masayoshi
• Format: Article
• Language: English
• Subjects: Ball milling; High density; High-strength; Low-cost process; Non-firing ceramics; Silica (SiO2); Surface activation
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2020.10.013

[Display omitted] •A strength of 270 MPa and Vickers Hardness of 2.1 GPa (214 Hv) were achieved.•Adding ethanol to the KOH aqueous solution caused particles to maintain more liquid.•Granules that maintained more liquid showed better compressibility.•Careful control of the liquid amount, compression load, and curing time were vital.•Particle-particle bridge strength determines the bulk strength. Reducing the sintering time/temperature has been long desired. A so-called “non-firing sintering” was previously introduced by authors, without using thermal energy. This method involves the chemical activation of powder surface via ball milling, however, the mechanical strength of solidified bodies by non-firing sintering method is still low. In this study, an optimized non-firing process will be proposed in order to achieve high-strength materials comparable to the high-temperature sintered counterparts. Results showed that by optimizing the process, mechanical strength of 270 MPa and Vickers hardness of 2.1 GPa (214 Hv) were successfully achieved. It is also shown that the particle-particle bridge strength determines the bulk strength.