Method for coating surface of ceramic metalized envelope with nickel
Technical field
The present invention relates to a kind of method for coating surface of ceramic metalized envelope with nickel.
Background technology
High voltage vacuum switchgear cabinet is widely used in the high voltage power transmission and transforming industry, and the core of high voltage vacuum switchgear cabinet is a high voltage vacuum interrupter, what be widely used at present is ceramic high voltage vacuum interrupter, and ceramic metalized envelope is one of critical component of high voltage vacuum interrupter.When ceramic metalized envelope is made, with the metal parts sealing-in time, have reliable sealing-in air-tightness and sealing strength in order to ensure ceramic metalized envelope, need be at ceramic cartridge surface applied layer of metal layer, behind high temperature sintering, form the metal layer of one deck densification, carry out nickel plating again in metallization layer then.What the method for general nickel plating adopted is traditional electronickelling technology, because electronickelling technology is relatively backward, the technical process product quality also is difficult to control, can not get effective processing if the more important thing is the electroplating wastewater of electronickelling, can pollute to environment.
Summary of the invention
The technical problem that the present invention solves: a kind of method for coating surface of ceramic metalized envelope with nickel is provided,, eliminates the electronickelling technology that falls behind by adopting the new nickel method that is coated with, stable and reliable product quality not only, method is simple, and environment-protecting clean.
The technical solution used in the present invention: will meet the nickel powder that quality index requires (granularity, purity); adopt different grain size to carry out grating; make paste by adding suitable binding agent; adopt the method for serigraphy directly to be printed on the surface of metal layer (control coating layer thickness) then; through 900 ℃~1200 ℃ high temperature sintering (atmosphere protection), reach combining closely of nickel dam and metal layer again.
Technological process is: preparation nickel powder-preparation nickel cream-serigraphy-sintering-finished product.
Concrete grammar is as follows:
A kind of method for coating surface of ceramic metalized envelope with nickel, implement according to following steps:
(1) preparation nickel powder: adopt varigrained carbonyl nickel powder to prepare burden, make the grain composition D of nickel powder
50Reach 1.5-2.5 μ m;
(2) preparation nickel cream: with the nickel powder that mixes according to nickel powder: the ratio system cream of binding agent=1: 0.4-0.6; Described binding agent adopts ethyl cellulose and terpinol according to 1: the ratio of 20-30 mixes;
(3) serigraphy: adopt silk-screen printing technique that nickel cream is printed on the metallization layer of ceramic metalized envelope, the silk screen specification is 100 orders-300 orders;
(4) sintering: the ceramic metalized envelope after the serigraphy is carried out sintering, and sintering temperature is 900 ℃~1200 ℃, is incubated 30 minutes, and protective gas is pure hydrogen or nitrogen hydrogen mixeding gas.
In the described step (1), the grain composition D of nickel powder
50Be 2.0 μ m.
In the described step (2), nickel powder: the ratio system cream of binding agent=1: 0.5; Described binding agent employing ethyl cellulose and terpinol mix according to 1: 30 ratio.
In the described step (3), the silk screen specification is 100 orders-200 orders.
In the described step (4), sintering temperature is 1000 ℃~1200 ℃.
The present invention compared with prior art replaces electronickelling technology with being coated with the nickel method, and not only stable and reliable product quality, and method is simple, obtains huge economic benefit and social benefit.
The specific embodiment
In order to change the process that tradition falls behind, the present invention adopts a kind of new nickel method that is coated with, only need to meet the nickel powder that quality index requires, make paste by adding suitable binding agent, adopt the method for serigraphy directly to be printed on the surface of metal layer then, pass through high temperature sintering again, reach combining closely of nickel dam and metal layer.The nickel dam that obtains like this has good solder wettability, sealing-in air-tightness and sealing strength with metal sealing the time.Concrete implementation step is as follows:
(1) preparation nickel powder: adopt varigrained carbonyl nickel powder to prepare burden, make the grain composition D of nickel powder
50Reach 1.5-2.5 μ m, preferred particulates grating D
50Be 2.0 μ m.
(2) preparation nickel cream: with the nickel powder that mixes according to nickel powder: the ratio system cream of binding agent=1: 0.4-0.6, preferred nickel powder: binding agent=1: 0.5; Described binding agent adopts ethyl cellulose and terpinol according to 1: the ratio of 20-30 mixes, preferred, ethyl: terpinol=1: 30;
(3) serigraphy: adopt silk-screen printing technique that nickel cream is printed on the metallization layer of ceramic metalized envelope, the silk screen specification is 100 orders-300 orders, preferred 100 orders-200 order;
(4) sintering: the ceramic metalized envelope after the serigraphy is carried out sintering, and sintering temperature is 900 ℃~1200 ℃, preferred 1000 ℃~1200 ℃, be incubated 30 minutes, and protective gas is pure hydrogen or nitrogen hydrogen mixeding gas.
Through said method be coated with nickel dam, nickel layer thickness 10~15 μ m, tensile value 〉=130Mpa, sealing-in leak rate≤1 * 10
-11Pam
3/ s, stable and reliable product quality not only, and also method is simple, and compliance with environmental protection requirements can obtain huge economic benefit and social benefit.