Secondary-emission rare earth-molybdenum material and its preparing process

An emissive material, secondary technology, applied in the direction of electrical components, exhaust connections/feeds, gas discharge tubes/containers, etc.

Inactive Publication Date: 2002-07-24
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

There are no reports about rare earth molybdenum secondary emission materials

Method used

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  • Secondary-emission rare earth-molybdenum material and its preparing process
  • Secondary-emission rare earth-molybdenum material and its preparing process
  • Secondary-emission rare earth-molybdenum material and its preparing process

Examples

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Effect test

example 1

[0013] Example 1, 3.32 grams of lanthanum nitrate and 11.07 grams of yttrium nitrate were dissolved in water respectively, and added to 120.02 grams of powdered MoO 2 in (where La 2 o 3 Accounting for 2.5% by weight of molybdenum, Y 2 o 3 The weight ratio of molybdenum is 7.5%), the doped MoO 2 The powder is kept at 500°C under hydrogen for 2 hours to decompose rare earth nitrates into rare earth oxides, and then doped MoO in a multi-stage hydrogen furnace at 800-1000°C 2 Powder reduced to doped La 2 o 3 and Y 2 o 3 The composite rare earth aluminum powder is made into a rare earth molybdenum rod with a certain size after pressing and sintering. After machining, a rare earth molybdenum sheet of φ10×1mm is made. Then laser welding is used to weld the rare earth molybdenum sheet with the molybdenum cylinder and the metal tungsten wire used for heating, and after exhausting and activation treatment, the rare earth molybdenum experimental magnetron is made. The secondary...

example 2

[0014] Example 2, 4.98 grams of lanthanum nitrate and 16.60 grams of yttrium nitrate were dissolved in water respectively, and added to 113.35 grams of powdered MoO 2 in (where La 2 o 3 The weight ratio of molybdenum is 3.75%, Y 2 o 3 The weight ratio of molybdenum is 11.25%), the doped MoO 2 The powder is kept at 500°C under hydrogen for 2 hours to decompose rare earth nitrates into rare earth oxides, and then doped MoO in a multi-stage hydrogen furnace at 800-1000°C 2 Powder reduced to doped La 2 o 3 and Y 2 o 3 The composite rare earth molybdenum powder is made into a rare earth molybdenum rod with a certain size after pressing and sintering. After machining, a rare earth molybdenum sheet of φ10×1mm is made. Then laser welding is used to weld the rare earth molybdenum sheet with the molybdenum cylinder and the metal tungsten wire used for heating, and after exhausting and activation treatment, the rare earth molybdenum experimental magnetron is made. The secondary...

example 3

[0015] Example 3, 6.64 grams of lanthanum nitrate and 22.14 grams of yttrium nitrate were dissolved in water respectively, and added to 106.68 grams of powdered MoO 2 in (where La 2 o 3 Accounting for 5% by weight of molybdenum, Y 2 o 3 The weight ratio of molybdenum is 15%), the doped MoO 2 The powder is kept at 500°C under hydrogen for 2 hours to decompose rare earth nitrates into rare earth oxides, and then doped MoO in a multi-stage hydrogen furnace at 800-1000°C 2 Powder reduced to doped La 2 o 3 and Y 2 o 3 The composite rare earth molybdenum powder is made into a rare earth molybdenum rod with a certain size after pressing and sintering. After machining, a rare earth molybdenum sheet of φ10×1mm is made. Then laser welding is used to weld the rare earth aluminum sheet with the molybdenum cylinder and the metal tungsten wire used for heating, and after exhausting and activation treatment, the rare earth molybdenum experimental magnetron is made. The secondary em...

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Abstract

A two-element rare-earth / molybdenum material as secondary emission material is characterized by that it contains La2O3 and Y2O3 in a weight ratio of 1:3, and is preapred through adding La2O3 and Y2O3in the form of aqueous solution of their nitrates to molybdenum oxide or Mo powder, treating in hydrogen at 500-550 deg.C for 1-5 hr, reducing at 800-1000 deg.C, and powder metallurgy to obtain said secondary emission material, which has advantages of high emission coefficient, stability and mechinability and high resistance to expose in atomosphere.

Description

1. Technical field [0001] A binary rare earth molybdenum secondary emission material and a preparation method thereof belong to the technical field of rare earth refractory metal cathode materials. 2. Background technology [0002] Traditional magnetron cathode materials use Ba-W cathodes, and a small amount of Th-W cathodes. The Ba-W cathode undergoes a variety of processes such as copper infiltration, processing, pre-firing, copper removal and salt infiltration, and the production process is cumbersome. Although the secondary emission coefficient of this type of cathode is above 2.0, because the cathode is a coating type thick film The cathode has poor bombardment resistance and therefore poor emission stability. Due to the high hardness of the metal tungsten matrix, it is impossible to machine the sintered body. Th-W cathode Since Th is a radioactive element, it will cause radioactive hazards to the human body in the process of material preparation, tube loading and dis...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C1/04C22C27/04C22C32/00H01J25/50
Inventor 王金淑周美玲张久兴聂祚仁左铁镛
Owner BEIJING UNIV OF TECH
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