Industrial ink jet printer heads have a number of submillimetric channels arranged along a well defined design in a small volume. Solid state diffusion bonding is investigated to bond in a single cycle and with a high degree of precision several metal foils in which 2D flow patterns are selectively etched or laser cut. Our approach may be considered original in a few respects: 1. diffusion bonding is carried without a hot press but makes use of the differential thermal expansion between the metallic foils and the TZM molybdenum tooling, 2. low diffusion bonding temperatures are used, less than 900°C, 3. the preparation of the faying surfaces is kept minimal and the atmosphere is inert or slightly reducing. No bonding difficulties were identified with nitrogen or with residual oxygen in the furnace An example is presented where the dimensions are 34×20×1.5 mm with 8 jet outlets and 6 austenitic stainless steel foils, (between 75 and 500 μm thick). The microstructural evolution and the defect issues are discussed. The operating performance of such a concept is satisfactory and leads the way to thinner and more complex designs.
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