High-Temperature Silicon Diffusivities in Mo₅Si₃ and W₅Si₃ Phases

Evolution kinetics and microstructure of MoSi2 and Mo5Si3 surface layers on two-phase Mo-9Si-18B alloy during pack-cementation and high-temperature oxidation

“…If it is the case, it must be the existence of B atoms that reduces the growth rate of the T 1 layer. The activation energy for the growth is calculated as about 220 kJ/mol, which is lower than the values (297-360 kJ/mol) reported in the earlier studies [13][14][15][16][17][18]; the reduction of the growth kinetics is more pronounced at higher temperatures.…”

“…Fig. 6(b) shows an Arrhenius plot of the growth rate constant as a function of the reciprocal temperature, together with the results of earlier studies [13][14][15][16][17][18] for comparison. The values of the present study fall at the lower bound of the data for the binary Mo-Si system reported by Tortorici [17].…”

“…The specimens were pack-cemented for 48 h. (b) Arrhenius plots of growth rate constants of the T 1 layer measured in this study and earlier studies[13][14][15][16][17][18] as a function of the reciprocal temperature.…”

Growth kinetics and oxidation behavior of WSi2 coating formed by chemical vapor deposition of Si on W substrate

“…The V and H values measured from CBED pattern of The XTEM results indicate that two W-silicide layers (WSi 2 and W 5 Si 3 ) in the W-Si system grow simultaneously at the early deposition stage of Si. Lee et al [23] and Kharatyan et al [24] reported that Si was the dominant diffusing element in the W 5 Si 3 layer formed by annealing treatment of WSi 2 /W diffusion couples at high temperatures. These results suggest that WSi 2 coating should be formed sequentially by chemical reactions (5W + 3Si → W 5 Si 3 + 7Si → 5WSi 2 ).…”

Reaction diffusion of MoSi2 and Mo5SiB2

“…The growth kinetics of the Mo 5 Si 3 layer in the ternary Mo-Si-B system appears to be slower than in the binary Mo-Si system. The activation energy for the growth is calculated as about 310 kJ/mol, which is similar to the values (297-360 kJ/mol) reported for the binary Mo-Si system [5][6][7][8][9][10], while is higher than the value of 220 kJ/mol for MoSi 2 /Mo-9Si-18B [3]. Fig.…”