Abstract: Nitrogen-strengthened alloys, especially steels, are produced by heating a combination of metal particles and a nitrogen donor, such as a chromium nitride, to make nitrogen available as a solute in the particles. The particles may be produced as a permeable preform for the process. The dissolved nitrogen leads to improved hardness, and higher strength is additionally obtained by the inclusion of a dispersant, such as yttria, in the particles.

Abstract: A control system for a single acting or double acting fluidic pump comprising a detector stage (1), a power amplifiction stage (2) and a primary element stage (3). The detector stage comprises bistable fluidic amplifiers for detecting pressure changes in a gas pressure line (10) to a displacement vessel of the pump. The power amplification stage comprises at least one unvented bistable fluidic amplifier to amplify and direct signals from the detector stage to the primary element. The primary element can be a jet pump (12) and vortex amplifier (13) to provide high pressures in the gas pressure line (10).