No abstract

Metal-organic frameworks (MOFs) are a class of solid crystalline materials formed by the self-assembly of organic ligands and metal ions or clusters through coordination bonds. Owing to their intrinsic rich...

Cf/SiC was successfully joined to Ti alloy with Ag–Cu–Ti–W, Ag–Cu–Ti–SiC and Ag–Cu–Ti–TiC mixed powders by some suitable brazing parameters. Microstructure and shear strengths of the preformed joint were investigated. The results showed that the W particulate and reaction products can uniformly distribute in the brazing layer of the performed joint. These composite brazing layers relaxed the thermal stress of the joint effectively. These characteristics were beneficial to the joint, which had shear strengths that were significantly higher than the optimal shear strengths of the joint brazed with pure Ag–Cu–Ti at room temperature and 500°C.

The phase compositions of high Ti bearing titanomagnetite sinter with different contents of B 2 O 3 were studied at 1623 K under an oxygen partial pressure of 5610 23 atm. The results showed that B 2 O 3 mainly gathered in Ca 2 SiO 4 phase and formed 2CaO.xSiO 2 .2/3(12x)(B 2 O 3 ) phase. The appearance of B 2 O 3 can restrain the precipitation of CaTiO 3 and 2CaO.xSiO 2 .2/3(12x)(B 2 O 3 ) and promote the amount of Fe bearing mineral phase in the current experimental condition. In addition, the shape of CaTiO 3 changed from bulk to strip type with the increase in B 2 O 3 content. The formula of silicoferrite of calcium and aluminium changed from 1?6CaO.4?9Fe 2 O 3 .Al 2 O 3 .1?8SiO 2 to 2?5CaO.5?9Fe 2 O 3 .Al 2 O 3 .2?6SiO 2 , and the formula of dicalcium (boron) silicate changed from 2CaO.SiO 2 to 2CaO.0?33SiO 4 .0?45B 2 O 3 when B 2 O 3 content was from 0 to 2?0 mass-% in the sinter. The change of phase compositions with the addition of B 2 O 3 in the sinter will be beneficial for improving its metallurgical properties.