Influence of Powder Treatment Methods on Sintering, Microstructure and Properties of Si3N4 - Based Materials

Microstructure and mechanical properties of silicon nitride ceramics prepared by pressureless sintering with MgO–Al2O3–SiO2 as sintering additive

“…[2][3][4][5][6][7] However, the traditional ball-milling techniques usually take a long time and produce green compacts with poor homogeneity. 12 Both chemical methods and wet mixing routes have been investigated with the aim to improve the homogeneity of the additives' distribution. [12][13][14][15][16] Advantages of the chemical methods, e.g., coprecipitation, coating of the additives in situ on Si 3 N 4 particles, are a better homogeneity of sintering aids and the consequent possibility to reduce the amount of additives.…”

“…12 Both chemical methods and wet mixing routes have been investigated with the aim to improve the homogeneity of the additives' distribution. [12][13][14][15][16] Advantages of the chemical methods, e.g., coprecipitation, coating of the additives in situ on Si 3 N 4 particles, are a better homogeneity of sintering aids and the consequent possibility to reduce the amount of additives. [12][13][14] However, in some cases the chemical processes are expensive, and there are some technological difficulties concerning their scale-up to industrial mass production.…”

“…[11][12] In fact, inhomogeneities generally formed at the earlier stage and became even larger during the subsequent processing, which causes strength degradation and lower reliability. 5 A crucial step is to find a powder blending route able to produce high homogeneity in powder mixtures.…”

“…[12][13][14][15][16] Advantages of the chemical methods, e.g., coprecipitation, coating of the additives in situ on Si 3 N 4 particles, are a better homogeneity of sintering aids and the consequent possibility to reduce the amount of additives. [12][13][14] However, in some cases the chemical processes are expensive, and there are some technological difficulties concerning their scale-up to industrial mass production. On the other hand, various wet mixing routes, e.g., mechanical, ultrasonic, and attrition mixing, have been used to introduce sintering aids in Si 3 N 4 suspensions and their impact on the surface composition and surface coverage were investigated.…”

Dry sliding wear behavior of nano-sized SiC pins against SiC and Si3N4 discs

“…The relative densities of n-SiC, -SiC and Si 3 N 4 were 100%, 98.5% and 100%, respectively. More details on processing and characteristics of the SiC samples are reported in [9] and [10] for the -SiC sample and n-SiC sample, and in [11] for the Si 3 N 4 sample. Some basic mechanical properties of the sintered ceramics are summarized in Table 1.…”