Friability test: min.10 bending
Micrographic analysis according to ASTM (American Society for Testing Materials) F68-93, Class 1 and 2
OFE-OK® is a grade of oxygen-free copper of very high purity, which is necessary in such high demands in industries such as electrical engineering, the production of electronic and vacuum equipment. Typical applications:
The OFE-OK® production follows the same technology as the OF-OK® production, but only the highest quality ingots are selected for this grade, and with this exceptionally strict quality control. Thus, absolutely quality material with a higher electrical conductivity and a very low level of impurities is guaranteed. The total content of impurities (including Ag) is not less than 40 ppm (0.0040%). To ensure the full resistance to hydrogen embrittlement, the maximum oxygen content in OFE-OK® is limited to 3 ppm (0.0003%). Usually the oxygen content in OFE-OK® is much lower. The content of chemical elements of volatiles in a vacuum at high temperatures, i.e. impurities harmful when used in electronic industry, very low.
High thermal and electrical conductivity of copper makes it difficult to weld (point and roller). This is especially true for massive products. Fine parts can be welded with tungsten electrodes. Parts with a thickness of more than 2 mm can be welded with a neutral acetylene-oxygen flame. A reliable method of joining copper products is soldering with soft and hard solders.
|Soft Condition||Semi-Solid Condition||Solid Condition|
|Hardness According to Vickers, HV||35 – 65||70 – 95||85 – 115|
|The tensile strength, MPa||200 – 220||250 – 350||260 – 400|
|0.2% Yield strength, MPa||35-65||180-280||220-380|
The main property of copper, which determines its preferential use is a very high electrical conductivity (or a low electrical resistivity). Such impurities as phosphorus, iron, arsenic, antimony, tin, significantly impair its electrical conductivity. The amount of electrical conductivity is significantly influenced by the method of obtaining a semi-finished product and its mechanical state.