The invention belongs to the field of magnetron design and production, and discloses a magnetron tube core for
microwave heating. The magnetron tube core comprises a heated
cathode emitter, an upper shielding cap, a lower shielding cap, a
bimetal center support and upper
electrode supply connecting rod, a side support and lower
electrode supply connecting rod, a lower magnetic pole, a tube core casing and high-tension
ceramic, wherein the upper shielding cap and the lower shielding cap are arranged on the heated
cathode emitter; the
bimetal center support and upper
electrode supply connecting rod is welded by
molybdenum as well as iron,
nickel and
cobalt constant-expansion
ceramic sealing
alloy; the side support and lower electrode supply connecting rod adopts iron,
nickel and
cobalt constant-expansion
ceramic sealing
alloy; and the high-tension ceramic is provided with sealing connection holes. According to the magnetron tube core for
microwave heating, the iron,
nickel and
cobalt constant-expansion ceramic sealing
alloy is adopted as
lower half sections of the side support and lower electrode supply connecting rod and the center support and upper electrode supply connecting rod, a coefficient of linear expansion of the iron, nickel and cobalt constant-expansion ceramic sealing alloy is very similar to that of the high-tension ceramic, and the
specific resistance of the iron, nickel and cobalt constant-expansion ceramic sealing alloy is far lower than that of
molybdenum, so that the magnetron tube core has the characteristics of simple sealing structure and
welding technology, good sealing performance, high reliability during working, long service life, high yield of production, lower cost and the like, and
electrical performance of the
cathode is improved to some extent.