Abstract
Joining of Mo and MoSi₂ with Mo and/or MoSi₂ by brazing with nickel was studied. Molybdenum disilicide was prepared by the reaction of liquid silicon with the Mo substrate at the temperature of 1530 °C and 3 min. Wetting of both Mo substrate and MoSi₂ was measured by sessile drop method; wetting angles were very low (close to zero). Products of interaction of Mo and/or MoSi₂ with Ni were studied by electron microscopy with energy-dispersive spectroscopy (EDS) and X-ray diffraction methods (XRD). Shear strength of the joints was measured by push-off method. The Mo-Ni-Mo system produced a joint with no cracking or porosity with the shear strength 134.5 MPa. MoSi₂-Ni-MoSi₂ joint due to different thermal expansion of materials being joined exhibited porous interface and catastrophic cracking through Mo₅Si₃ with the shear strength 37.0 MPa.

Key words
molybdenum disilicide, wetting, joining, shear strength

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