JPS6320294B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improvement in a brass-based electrode wire for electrical discharge machining. Conventionally, brass wires have been commonly used as electrode wires for electric discharge machining, but recently many attempts have been made to increase the speed of electric discharge machining in order to shorten machining time in order to improve productivity. Electrical discharge machining speed is determined by the equipment (electrical discharge machine)
The process greatly depends on the performance of the wire and the properties of the electrode wire, and the latter in particular has the potential to dramatically increase the processing speed. For this reason, there has recently been a particularly active development in improving the properties of electrode wires, but nothing that can be put to practical use in terms of performance and cost has yet to be found. By the way, brass wire is suitable as an electrode wire for electrical discharge machining because the alloy component Zn improves discharge properties and has greater high-temperature strength than copper wire, which was widely used before. This is because machining can be performed at a relatively high speed while maintaining state and dimensional accuracy. Examples of wires that can be processed faster than brass wires include tungsten wires, molybdenum wires, and other copper alloy wires, but all of them have the drawback of being difficult to process and expensive. Therefore, a practical electrode wire could be one that improves the properties of the current brass wire, and one way to do this is to add elements to the alloy that improve discharge performance, maintain high-temperature strength, and make it easier to process. is possible. In view of the above, an object of the present invention is to provide an electrode wire for electric discharge machining that can significantly improve discharge characteristics by improving the composition of a brass-based alloy. That is, the gist of the present invention is that Zn
20~50%, one of Ni, Co, and Si 0.2~
1.0% and 0.2 of any one of Ag, Sn, Pb, and Sb
Including ~1.0% and totaling 0.5~2.0%
The electrode wire for electric discharge machining is characterized in that the electrode wire contains Cu and the remainder is Cu. Here, regarding Zn content, if it is less than 20%,
No improvement in discharge performance can be expected by adding Zn, and if it exceeds 50%, processability such as wire drawing will be significantly reduced. The contents of Ni, Co, and Si are limited to 0.2 to 1.0%, while the contents of Ag, Sn, Pb, and Sb are also limited to 0.2 to 1.0%. That is, Ni,
Co and Si are added mainly to increase high-temperature strength, and Ag, Sn, Pb, and Sb are added to improve discharge performance, but both of these two types of additive elements are not necessary in the present invention. be. Here Ni,
Considering the case where Co and Si are added alone, if the content is less than 0.5%, no improvement in discharge properties or high-temperature strength can be expected, and if it exceeds 2.0%, workability such as wire drawing will be significantly reduced. On the other hand, Ag,
Considering the case where Sn, Pb, and Sb are added alone, if the content is less than 0.5%, no improvement in discharge performance can be expected, and if the content exceeds 2.0%, workability such as wire drawing will deteriorate in the case of elements other than Ag. , In the case of Ag, the improvement in discharge performance is slight (2.0% is considered to be the practical limit from a cost perspective)
becomes. However, in reality, both of these two types of added elements are necessary in the present invention as described above, and therefore, when considering the case where they are added in total, the added content of each type of element is It is approximately 0.2 to 1.0%. The present invention will be further explained below with reference to Examples shown in the table. Diameter 150mm, length obtained by melting the alloy shown in the table
A 300mm billet is hot extruded into a 10mm diameter generatrix, which is then wire drawn to a final diameter of 0.25mm.
It was made into a thin line. An electric discharge machining test was conducted using the thin wire as an electrode wire. A plate material with a thickness of 25 mm was used as the test workpiece, and the test was conducted under the conditions of a power supply voltage of 130 V and a wire tension of 800 g. The test results were evaluated based on extrusion and wire drawability, degree of wire wear during electrical discharge machining, and maximum practical machining speed. Here, the machining speed is also expressed as a relative ratio when the maximum machining speed of the Cu-Zn binary alloy is set to 1.00. Therefore, if this value is greater than 1.00, it indicates a higher processing speed than conventional brass wire, and if this value is smaller than 1.00, it indicates a lower processing speed than conventional brass wire. The symbols in the wire drawability column in the table have the following meanings. ○: Good wire drawing △: Slightly difficult wire drawing ×: Very difficult wire drawing

【table】

[Table] As explained above, according to the present invention, an extremely practical electrode wire that can be easily machined and significantly improve the electric discharge machining characteristics, particularly the electric discharge machining speed, has been created by improving the alloy composition based on brass. Obtainable. Further, according to the electrode wire, it is possible to reduce heat generation due to machining as the speed of electrical discharge machining increases, so that it is possible to improve the surface condition and dimensional accuracy of the workpiece.

Claims (1)

[Claims] 1 Weight percentage of 20 to 50% Zn, 0.2 to 1.0% of any one of Ni, Co, and Si, and Ag, Sn, Pb, and Sb
An electrode wire for electrical discharge machining, characterized in that it contains 0.2 to 1.0% of any one of the following, and the total of the elements other than Zn is 0.5 to 2.0%, with the remainder being Cu.