Sublimation of volatile components of electrolessly reduced Ni-B alloys: Kinetics and mass spectrometry

The composition of volatile compounds sublimating at 20-700 degreesC from electrolessly plated Ni-B alloys containing 6.2, 19.6, or 20.8% of boron and either freshly-deposited or subsequently-oxidized, as well as the kinetics of the sublimation, is studied by a precise thermogravimetry technique with an automatic vacuum microbalance combined with a quadrupole mass-spectrometer. The effect of the sublimation on the kinetics of the high-temperature oxidation of the alloys is also investigated. Boron oxides and water mainly sublimate from all the alloys; concurrently, NiB3 also sublimates from fresh deposits at a temperature higher than 600 degreesC.