At a sintering temperature of 2150 ℃, phenolic resin 2.0% + boron carbide 2.5%, according to the formula to choose A2: A1 (4: 1), A2, A3: A1 (4: 1), A3 four kinds of powder Experiments were carried out and the average particle size was about 0.8 μm, 1.0 μm, 1.6 μm, 2.0 μm in order to study the influence Gas Sintering Silicon Nitride Machined Plunger Shaft Pistonof powder particle size on the sintering and densification of silicon carbide ceramics. Let's analyze the conclusion for everyone below.
Compared with single powder sintering, the combination of SiC ceramic particles after coarse/fine mixed powder sintering has finer grains and tighter combination. Due Gas Sintering Silicon Nitride Machined Plunger Shaft Piston to the moderate difference in particle size of the coarse and fine powder used, the fine particles can be better filled to In the pores between the coarse particles, the grain size after sintering is relatively uniform, the distribution of carbon and pores is relatively uniform, and there is no obvious aggregation and abnormal grain growth;
The coarse particles used are larger than the particle size, which makes the filling of the fine particles insufficient. Therefore, it can be observed that the grains are not tightly combined, the size is different, and the pore distribution is uneven after sintering. When a single powder is used for sintering, After sintering, the grains of the powder with finer particle size are intertwined and grow, and the Gas Sintering Silicon Nitride Machined Plunger Shaft Piston combination is tighter, and the pore distribution is more uniform, while the powder with coarser particle size is sintered, and there are some grains with different sizes and uneven distribution of pores. And there is a tendency to increase.
The flexural strength and density of samples sintered with coarse/fine mixed powders are higher than those sintered with single powders. This result is consistent with the microstructure. Among them, the density and flexural strength of the sintered SiC ceramic sample reached 3.11 g/cm3 and 428 Mpa, which were slightly larger than the sample after sintering with a single powder.
Although there is still a big gap between Gas Sintering Silicon Nitride Machined Plunger Shaft Piston its mechanical properties and samples sintered with a single powder, it can still provide an idea for low-cost atmospheric sintered SiC ceramics, indicating that if the particle distribution of coarse/fine powder is optimized, a reasonable After the proportion, it is very possible to use part of the mixed powder to replace all the fine particles to achieve atmospheric densification and sintering of SiC ceramics.
What is the effect of powder particle size on the densification of ceramic sintering?
2020 09/14