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Components
Published in Douglas Self, Small Signal Audio Design, 2020
Copper is normally used as a very dilute alloy known as electrolytic tough pitch (ETP) copper, which consists of very high purity metal alloyed with oxygen in the range of 100 to 650 ppm. In view of the wide exposure that the concept of oxygen-free copper has had in the audio business, it is worth underlining that the oxygen is deliberately alloyed with the copper to act as a scavenger for dissolved hydrogen and sulphur, which become water and sulphur dioxide. Microscopic bubbles form in the mass of metal but are completely eliminated during hot rolling. The main use of oxygen-free copper is in conductors exposed to a hydrogen atmosphere at high temperatures. ETP copper is susceptible to hydrogen embrittlement in these circumstances, which arise in the hydrogen-cooled alternators in power stations. Many metals are subject to hydrogen embrittlement, including steel, which makes it a difficult gas to deal with.
Components
Published in Douglas Self, Small Signal Audio Design, 2014
Copper is normally used as a very dilute alloy known as electrolytic tough pitch (ETP) copper, which consists of very high purity metal alloyed with oxygen in the range of 100 to 650 ppm. In view of the wide exposure that the concept of oxygen-free copper has had in the audio business, it is worth underlining that the oxygen is deliberately alloyed with the copper to act as a scavenger for dissolved hydrogen and sulphur, which become water and sulphur dioxide. Microscopic bubbles form in the mass of metal but are completely eliminated during hot rolling. The main use of oxygen-free copper is in conductors exposed to a hydrogen atmosphere at high temperatures. ETP copper is susceptible to hydrogen embrittlement in these circumstances, which arise in the hydrogen-cooled alternators in power stations.
Effect of Ni on the microstructure and properties of Sn-6.5Zn-3.0Bi solders
Published in Philosophical Magazine, 2022
Xiaohui Wang, Zhuhuan Yu, Yawen Yan, Wei Gao, Xuliang Liu, Wei Du
Spreading tests were used to evaluate the effect of Ni on the wettability of Sn-6.5Zn-3.0Bi solders on Cu. The samples of wettability testing were prepared using a wire cutting. The weight range of the samples was 0.12±0.004g. The samples were placed in the centre of oxygen-free copper and a wettability test was carried out in a SX2-9-17TP resistance furnace at 260 °C. The solders were kept for 2 min after melting and cooled naturally after being removed. The spreading area of the solder alloys on the oxygen-free copper was measured with Image pro plus. Each solder alloy was tested 5 times and the average value was taken. The spreading rate was calculated according to the following formula: where A is the area of the original sample, and Á is the spreading area after the solder was spread on the Cu.
An Experimental Investigation on the Influence of Copper Ageing on Flow Boiling in a Copper Microchannel
Published in Heat Transfer Engineering, 2020
Prasanna Jayaramu, Sateesh Gedupudi, Sarit K. Das
Figure 2 shows the test section made of an oxygen-free copper. The copper microchannels considered in this study are of two different sizes, one 0.5 mm wide ×0.24 mm deep and the other 1 mm wide ×0.49 mm deep, both 40 mm long, and machined using end milling. To eliminate the heat transfer to inlet and outlet plenum areas, plenums were fabricated in the Teflon insulation block and microchannel was aligned with them. Seven K-Type thermocouples of 1 mm diameter were inserted into the copper block 3 mm below the channel bottom to obtain surface temperatures along the channel. Test section included a transparent top cover plate (Polycarbonate Lexan), Teflon insulation block surrounding the copper block and cartridge heater. The microchannel was heated using a 130 Watt cartridge heater inserted in the copper block. Pressure transmitters were used to measure the inlet pressure and pressure drop across the microchannel. Uncertainties of the measured quantities and the derived quantities are shown in Table 1.
Heat Transfer Characteristics and Flow Visualization during Flow Boiling of Acetone in Semi-Open Multi-Microchannels
Published in Heat Transfer Engineering, 2019
Guodong Xia, Yue Cheng, Lixin Cheng, Yifan Li
As shown in Figure 3(a), the test section consists of a steel plate, a Pyrex7740 glass top cover, one-piece microchannels copper heating block, a bottom housing, an O-ring, electrical cartridge heaters, silicone gaskets, and an insulating base. Microchannels are incised on the oxygen-free copper heating block to greatly reduce the contact thermal resistance. Below the top surface of the heating block, there are three horizontal holes that are equally ranged up in order of distance. The K-type thermocouples (TJ60-CAXL-032U-4) are implanted in the holes to measure the temperature of the microchannels for places. Three other K-type thermocouples are vertical, equally spaced, and are used to evaluate the heat flux. The copper block and the bottom housing are tightly assembled to prevent displacement. Silicone rubber is used in the gap between the heating block and bottom housing to guarantee a good seal. Four electrical cartridge heaters are housed in the bottom holes of hte copper heating block to provide stable heat flux.