|Resistivity* (Ohm mm2/m)||0.0203||0.0221|
|Electrical Conductivity* (% IACS)||85||78|
|Tensile Strength* (N/mm2)||230||650|
|Temperature Coefficient of Resistance (1/°C)||0.00320||0.00320|
* Data depend on coating conditions, degree of cold working and thermal treatments during manufacturing process
Very high electrical conductivity
Due to the alloy portion in LEONI Histral® H77 being very low, there is just a slight decrease in resistance if compared with pure copper. Thus, the material preserves its high electrical conductivity while also featuring a great mechanical strength. Therefore, the material lends itself perfectly to strands where the very low diameter or cross-section must not lead to inadequate tensile strength.
Good mechanical strength
LEONI Histral® H77 is counted among the so-called “low-alloyed copper products“, the copper portion of which is 99.8 % of copper, with no more than the remaining 0.2 % covered by alloy additives (mainly magnesium in this case). Having been hard-drawn, its mechanical properties even improve, without the very good electrical qualities being impaired. This phenomenon allows for a significant reduction of cross-sections. Consequentially, Histral® H77 lends itself well to applications in which reduced weight plays a primary role. A prime example for this are signal cables, but also shielding braids, both of which require an above-average mechanical strength in order for the actual conductor to be sufficiently protected.
Flex Life properties
Alloys are usually employed in hard condition. LEONI Histral® H77 boasts excellent Flexlife properties, which ensure highest stability in any environment that is exposed to a lot of vibration and motion.
The crimp qualities of LEONI Histral® H77 correspond to those of pure copper in hard condition. However, the tools applied have to be adapted to the lower cross-sections.
The outstanding properties of LEONI Histral® H77 translate into much lower cross-sections supporting the same breaking load if compared to pure copper. For a breaking load of 70 N a pure copper strand must have a cross-section of 0.35 mm2, whereas the comparable value for a strand made out of Histral® H77 is 84 N at a cross-section of only 0.13 mm2, by means of which a weight reduction by 63 % can be achieved!
- Using weight as a reference value, a copper strand requires 0.0445 (g/m) per each 1 N of breaking load, with Histral® H77 attaining the same breaking load at a weight of just 0.0136 (g/m).
Pure copper in hard condition is susceptible to re-crystallization even at room temperature, at which it already begins to soften again resulting in a loss of mechanical strength. Adding on small quantities of alloys will suffice to vastly increase the point of re-crystallization of hard-drawn materials so that the greater strength is maintained in the event of higher ambient temperature, too. LEONI Histral® H77 has a much better thermal stability than pure copper. Hence, it is also suited for those applications that are subjected to elevated temperatures.
LEONI Histral® H77 has a slightly higher resistance than pure copper, while still boasting a conductivity of 85 % IACS (in soft condition).
The emphasis is more and more shifting towards environmental protection and husbanding of resources, with the focus revolving around the minimization of weight and consumption accompanied by heightened standards of safety and comfort. The growing use of electronic assistance systems constitutes a major step in this direction, which entails an increasing demand for signal cables. At the same time, the space accorded to cable harnesses is declining because of optimized safety systems. Signal cables made from LEONI Histral® H77 have the potential to render an important contribution to overcoming this predicament.
Data cables / Signal cables
Its small alloy portion reduces the resistance value of LEONI Histral® H77 no more than a little, as compared with pure copper. Thus, the very good electrical conductivity of the material remains unaffected whilst its excellent mechanical strength persists. This makes it a perfect fit for data cables and signal cables featuring very low diameters and cross-sections, but also a sufficient tensile strength.
Automation technology / Industrial applications
LEONI Histral® H77 boasts excellent Flexlife properties, which ensure highest stability in any environment that is exposed to a lot of vibration and motion.
The connection cables of loudspeaker membranes are exposed to extremely strong vibrations. LEONI Histral® H77 lends itself well to this application owing to its great mechanical strength in combination with a very good conductivity, in particular as a substitute for cadmium-containing alloys used in the past.
On account of its outstanding mechanical properties, LEONI Histral® H77 will not pose any problems when processed downstream into wires as fine as 0.025 mm (AWG 50). It keeps its conductivity level and remains an alloy that is highly suitable for being electro-plated.