X-ray tube cathode assembly and interface reaction joining process

An x-ray tube cathode assembly comprising:

• a support arm comprising a first metal;
• a ceramic insulator having a first metalized surface wherein the metalized surfaces comprise a desired amount of the first metal;
• a first member of filler material in contact with the support arm and the first metalized surface of the ceramic insulator, the first member of filler material comprising at least a second metal wherein a first alloy system comprising the first and second metals includes an alloy minimum point percentage composition of the first and second metals having a first alloy system minimum melting point for the alloy minimum point percentage composition that is lower than both of the melting point of the first metal and second metal;
• a bonding region resulting from heating the cathode assembly causing diffusion bonding to proceed, the bonding region having a layer of alloy comprising the minimum point percentage composition, the heating of the cathode assembly continuing to a bonding temperature of at least the first alloy system minimum melting point and holding at that temperature for a desired period of time.

An x-ray tube cathode assembly comprising:

• a support arm comprising a sufficient amount of a first metal for diffusion bonding with a different second metal to form a first alloy system;
• a ceramic insulator having a first metallized surface;
• and
• means for securing the support arm to the ceramic insulator, the means for securing comprising a metal sheet comprising a third metal, the metal sheet plated on each side with the second metal, the third metal a different metal than either of the first and second metals, the means for securing disposed at an interface between a first surface of the support arm and the first metallized surface of the ceramic insulator, wherein a portion of the first alloy system including a percentage composition of the first and second metals that has a minimum melting point that is lower than both of the melting point of the first metal and second metal.

An X-ray tube comprising:

• an evacuated envelope;
• an anode assembly located within the evacuated envelope;
• and
• a cathode assembly located within the envelope in operative relationship to the anode assemble, the cathode assembly comprising:
• a support arm comprising a sufficient amount of a first metal for diffusion bonding with a different second metal;
• a ceramic insulator having a first metallized surface and an opposite facing second metallized surface;
• and
• means for securing the support arm to the ceramic insulator, the means for securing comprising a metal sheet comprising a third metal, the metal sheet plated on each side with the second metal, the third metal a different metal than either of the first and second metals, the means for securing disposed at an interface between a first surface of the support arm and the first metallized surface of the ceramic insulator, wherein a portion of an alloy including the first and second metal comprises a percentage composition of the first and second metals that has a minimum melting point for the percentage composition that is lower than both of the melting point of the first metal and second metal.