An investigation of the synthesis of nickel aluminides through gasless combustion

Preparation of titanium diboride TiB2 by spark plasma sintering at slow heating rate

“…An important criterion for the classification of a reaction is the value of the heating rate. Lower heating rates increase the conversion rate by solid-state reactions and inhibit solid-liquid processes that are necessary for self-sustaining interaction [11,12]. A self-sustaining reaction between Ti and amorphous ARTICLE IN PRESS B within the SPS setup is possible at heating rates higher than 100 1C/min.…”

Reaction synthesis of Ni-Al-based particle composite coatings

“…The morphological development of EMMC coatings during heat treatment is similar to that found in synthesis of bulk nickel aluminizes by powder metallurgy [10,11]. However, in EMMC coatings, only one component is in particulate form (Al) while the other component is present as a surrounding matrix (Ni).…”

“…Also, the number of peaks found has been shown to depend on heating rate (heating rate was 10°C/min in this study). Philpot et al [10] found two reaction peaks for samples with a slow heating rate (l°C/min) and only one peak for samples with a faster heating rate (5°C/min). The final microstructure (after heating to the final temperature) was the same in both cases.…”

“…However, the final coating microstructure is y(Ni) + Ni3A1. Philpot et al [10] showed significant diffusional reactions could take place both before and after tie observed reaction peak(s). In addition, Nishimura and Liu [19,20] showed that Ni3Al formation proceeds through several steps from the aluminum side of the phase diagram toward Ni3A1.…”

Finite-difference modelling of self-propagating high-temperature synthesis of materials

“…The weak exothermic reactions, such as Si + C ---* SiC and Ti + Ni -+ TiNi lie well within the "No SHS" zone and the "thermal explosion" method must be used to produce a reaction. reactions, Tstar t = 298 K unless indicated Si + C ~ SiC [28] Ti + Ni ~ TiNi [29] 9Cu + 4A1 ~ Cu9A14 [30] 3ZrO2 + 4AI + 3C----~ 3ZrC + 2A1203 [15] Ti + AI---~ TiAI [31] Mo + 2Si ---* MoSi 2 [32] 2Ni + Si --4 Ni2Si [33] Ni + AI ---* NiA1 [34] Ti + C--~ TiC [35] Ti + 2B ~ TiB 2 [36] 3TiO 2 + 4A1 + 3C ---* TiC + 2A1203 [15] ( The effect of preheating on the SHS reaction Ti + AI ~ TiAI can also be seen in Table 3. It has been reported by Yi et al [31] that preheating above 373 K is required to produce a steady SHS reaction.…”