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This work reports on the development and the experimental proof of a novel concept of miniaturized X-ray source. This concept is based on microsystems technology and carbon nanotube electron field emitters. Thereby, unseen features such as fast switching and reduced imaging time will be enabled in future applications, such as, for instance, static computed tomography. In this work we describe the fabrication, assembly, and testing of micro-fabricated electrodes and carbon nanotube cold cathodes, based on a new design concept, to be packaged in a miniaturized X-ray source. The source design concept was experimentally validated. X-rays were generated with a total current of up to 4 μA extracted from the cathode and an acceleration voltage of 3.1 kV. The total current collected on the anode was 0.2–0.4 μA which thus corresponds to a collection efficiency on the anode of approx. 10%. The components were assembled and operated in a high vacuum chamber at −6 mbar. The achieved results from both, the electron and the X-ray emission experiments will be discussed in detail. Furthermore, we comment on the individual components’ limitations as well as on the next steps to be taken in order to optimize the characteristics and performance of the final X-ray source.

Active brazing is an effective technique for joining diamond or cBN grit to metallic substrates. This technique is currently used to manufacture superabrasive, high-performance tools. The investigation of interface reactions between diamond and active brazing alloys plays an important role in understanding and improving the brazing process and the resultant tool performance. Focused ion beam (FIB) milling enabled the high resolution investigation of these extremely difficult to prepare metal–diamond joints. The interfacial nanostructure is characterized by the formation of two layers of TiC with different morphologies. First a cuboidal layer forms directly on the diamond and reaches a thickness of approximately 70 nm. Then a second layer with columnar TiC crystals grows on the first layer into the brazing filler metal by a diffusion-controlled process. The combined thickness of both TiC layers varies between 50 nm and 600 nm depending on the brazing temperature and holding time.

The commercial active brazing alloy “Incusil-ABA” was used for the bonding of diamond grits in order to assess their suitability for high performance machining tools. It was found that the microstructure of the brazing alloy matrix consisted of primary precipitates of Cu in a Ag–Cu eutectic matrix and an additional Cu–In–Ti rich intermetallic phase. Interface characterisation revealed the presence of a Ti-rich interfacial layer between the diamond and the alloy matrix. Therefore, good wettability was obtained for the embedded diamond grit particles. This intervening layer comprised nanosized cuboidal TiC which seemed to have acted as a precursor to its formation and fine metastable needles that were identified as cubic Ti3InC. Furthermore it was demonstrated that a three phase crystallographic orientation relationship had been obeyed at the interfacial region between the diamond, TiC and Ti3InC.