JPS6058769B2 - contact material - Google Patents

Description

[Detailed description of the invention] This invention relates to contact materials.

Conventionally, Ag-CdO contact materials, Ag-SnO far-point materials, and Ag-Ni contact materials have been used in various electrical devices such as electromagnetic contactors and relays. Among these contact materials, the Ag=Cd0 contact material and the Ag-SnO2 contact material have excellent welding resistance and wear resistance, and the Ag-Ni contact material has excellent wear resistance and processability. however,
All of these contact materials have the disadvantage that when used for no-fuse breaking force, the large current that flows during a short circuit creates an arc, and the arc is not cut sufficiently, resulting in poor short-circuit breaking performance. , improvement was desired. The inventors thought that there was a way to overcome these drawbacks of Ag-based contact materials, and as a result of investigating various metal oxides that could improve arc cutting, they found Li.

o was found to be superior. As a result of further research, we found that sno2
, In2o3 was found to be effective, and these and L
The inventors have discovered that a contact material with excellent welding resistance, wear resistance, and arc properties can only be obtained by using i20 in combination, and has thus arrived at this invention.
Therefore, in the present invention, lithium oxide, tin oxide, and indium oxide are contained in the silver base material, and the total amount of these lithium oxide, tin oxide, and indium oxide is It is expressed as the total amount of the elements Li, Sn, and In in the material, and the Li element in the lithium oxide is 0.1 to 0.1 to the sum of this total amount and the amount of Ag in the silver substrate. The content of the lithium oxide is set to 3% by weight, and the Sn element in the tin oxide and the In element in the indium oxide are each 0.2% by weight or more and the total amount of both is 12% by weight. The gist of the present invention is a contact material in which the contents of the tin oxide and the indium oxide are set to be equal to or less than % by weight.

The contact material of the present invention can be manufactured based on a general method for manufacturing silver-metal oxide contact materials.

That is, it can be produced by melting silver, lithium, indium, and tin in a predetermined ratio to create an alloy, and applying an internal oxidation method to this, and also producing silver powder, indium oxide powder,
It can also be manufactured by a powder sintering method in which lithium oxide powder and tin oxide powder are mixed, compressed, molded, heated and sintered to manufacture the contact material. When manufacturing contact materials by applying the internal oxidation method, adding iron group elements (Fe, CO, Ni) will improve the welding resistance and resistance of the resulting contact materials due to the grain refinement effect of iron group elements. Characteristics such as consumability will improve.

Next, the relationship between the content of metal oxide contained in the contact material according to the present invention and the properties of the contact material will be explained.

That is, the total amount of lithium oxide, tin oxide, and indium oxide is expressed as the total amount of Li, Sn, and In elements in each oxide, and this total amount and the amount of Ag in the base material are added. L in lithium oxide relative to the amount
The content of lithium oxide is set so that the i element is 0.1 to 3% by weight (hereinafter abbreviated as 1%), and the Sn element in the tin oxide and the In element in the indium oxide are respectively The contents of tin oxide and indium oxide are set so that the total amount of both is 0.2% or more and 12% or less. The content ranges of tin oxide and indium oxide are shown in the drawings. If the content of lithium oxide falls below the above range, the effect of improving arc characteristics will be reduced, and if it exceeds the above range, the specific resistance of the contact material will increase, resulting in poor welding resistance and wear resistance. Become. In addition, if the content of tin oxide and indium oxide is less than 0.2% based on Sn and In elements, the resistance is high! weldability,
The effect of improving wear resistance becomes smaller, and the total amount of both S
When it exceeds 12% based on n element and indium element, arc characteristics deteriorate. When using an iron group element, it is preferable to set the iron group element to account for 0.05 to 1.0% of the total. If it is less than 0.05%, the effect of its use will be small, and if it exceeds 1.0%, iron group elements will segregate at grain boundaries, resulting in poor welding resistance and wear resistance of the contact material.

Note that even if an iron group element is used, the contents of the lithium oxide, tin oxide, and indium oxide are not affected in any way. As described above, the contact material of the present invention has good adhesion resistance and abrasion resistance because the silver base contains predetermined amounts of lithium oxide, tin oxide, and indium oxide. It is excellent and also has excellent arc cutting properties. Next, examples will be described together with comparative examples.

[Example, comparative example]

Li, Sn, In, and Ni were blended with N so that Li(5Sn(51nI:.Ni) was contained in the amount shown in the following table, and the mixture was melted and alloyed in an argon atmosphere.

Separately, the above-mentioned alloys that did not contain only Ni but had Li, Sn, and In mixed with Ag in the proportions shown in the following table were also alloyed in the same manner. next,
This was placed in a mold and cast to form a bar material, which was annealed at 750° C. in an N2 atmosphere, followed by pressure bonding and rolling into a 1 wrm thick plate material. Next, this was internally oxidized. Internal oxidation was carried out at 750°C, 10(2) in 02 atmosphere.
I went under conditions between. Next, this was punched out into a contact shape and then brazed to make a sample. The samples thus obtained were subjected to short circuit tests and ASTM tests. The results are shown in the table below, and the example products had a shorter arc sticking time, better arc breakage, and better abrasion resistance and welding resistance than the comparative example products. Note that the short circuit test and ASTM test were conducted as follows. (Short circuit test) The sample was assembled into a no-fuse breaker, a short circuit test was conducted, and the arc sticking time was measured.

This arc stagnation time is the time during which an arc generated between a pair of contacts remains as it is. Electromagnetic force is generated at the same time as an arc is generated, but if the arc sticks for a long time, the time that a pair of contacts is connected by the arc increases, eventually leading to thermal breakdown of the contacts. Therefore, the shorter the arc sticking time, the better the short circuit breaking performance. In addition, the short circuit current is 5.2KA
I went there. (ASTM Test) A sample was run on an ASTM test machine and tested under the following conditions.

Load: AC single phase 100V 30A Contact force: 200y, separation force: 340y Contact shape: Movable φ5, 12R ball Fixed φ5, flat Final number of opening/closing: 50,000 times Number of pieces: 3 The amount of wear is the average value of 3 pieces, welded 3 pieces It is expressed as the total number of welds.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing is an explanatory diagram showing the content range of tin oxide and indium oxide.

Claims (1)

[Claims] 1 Lithium oxide, tin oxide and indium oxide are contained in the silver base, and the total amount of these lithium oxide, tin oxide and indium oxide is calculated by calculating the total amount of Li, Sn and indium oxide in each oxide. Expressed as the total amount of the In element, the Li element in the lithium oxide is 0.1 to 3% by weight with respect to the sum of this total amount and the amount of Ag in the silver base. The content of the lithium oxide is set such that the Sn element in the tin oxide and the In element in the indium oxide are each 0.2% by weight or more and the total amount of both is 12% by weight or less. A contact material having a set content of the tin oxide and the indium oxide.