High-performance LaB6 single crystal cathode for electron beam welding

This study investigates the fabrication of directly heated LaB6 cathodes, with a focus on their applicability in high-power electron-beam welding guns. Experimental results reveal that the LaB6 cathode achieves a current density of 30 A/cm² at 1627 °C – a temperature 1000 °C lower than that required by W cathodes for comparable performance. Quantitative measurements show the LaB6 cathode produces welds with a depth-to-width ratio of 20:1, doubling the 10:1 ratio achieved with the W cathode.