X-ray tubes and methods of making the same

A rolling contact bearing assembly is provided. The bearing assembly includes an inner ring and an outer ring concentrically disposed about the inner ring. The bearing assembly further includes a plurality of rolling contact elements disposed between the inner and outer rings, where at least one of the inner ring, the outer ring and the rolling elements having a solid lubricant coating disposed thereon. The bearing assembly further includes a gallium-based cooling solution disposed between the inner and outer rings and in contact with the rolling contact elements.