Optimizing the Mechanical Properties of Al-Mg Alloy Wire- Changzhou Yuzisenhan Electronic Co., Ltd

Optimizing the Mechanical Properties of Al-Mg Alloy Wire

Aluminum Magnesium Alloy Wire is a bimetallic wire consisting of an inner copper layer and an outer aluminum-magnesium alloy layer. It is used as shielding braided conductor for radio-frequency cables, leakage cables and computer data cables. The alloy layer provides better conductivity, while the copper layer offers improved corrosion resistance. The wire is also characterized by its high strength. The addition of manganese increases the strength somewhat through solution strengthening and improves strain hardening without appreciably reducing ductility or corrosion resistance.

The tensile properties of copper-clad aluminium magnesium alloy are influenced by heat treatments and aging processes. A series of studies have been conducted to explore the optimization of these factors, and the results show that the amount of Mg and Si in the alloy has a strong influence on the shaping of its mechanical properties.

Mg and Si content affects the value of both the linear factor K and the power factor n. The former influences the extent of strain hardening and the latter the rate of aging. The strain hardening exponent n is proportional to the square root of the stress intensity factor (SIF), which is directly dependent on the stress and strain level. The higher the SIF is, the greater the degree of strain hardening and the higher the tensile strength.

In order to achieve high tensile strength, the additive must have an equiaxed microstructure. The process parameters such as welding current, welding speed and gas flow rate play a vital role in achieving the desired tensile properties. Among these, the interlayer residence time is particularly crucial for optimizing the microstructure.

By reducing the interlayer residence time, the amount of arc melting wire is lessened and the resulting heat input into the additive is reduced, which helps to refine the grain size and form an equiaxed structure. The optimum process conditions for a high transverse tensile strength of the additive are found to be 90 A welding current, 700 mm/min welding speed, 22.5 L/min gas flow rate and 5 min interlayer residence time.

The tensile properties of the additive are highly anisotropic, with different transverse and longitudinal tensile strengths. The reason is that during the arc welding process, the transverse direction of the additive is heated to melt and supercooled to crystallize, while the longitudinal direction is not. To solve this problem, WAAM-CMT technology was applied. By utilizing variable polarity CMT, Geng H [27] was able to achieve a high transverse tensile test result of 382 MPa by using 5A06 aluminum alloy and a WAAM process with a reciprocating walking path. This method was able to reduce the formation of porosity and achieve better transverse and longitudinal tensile strengths than conventional welding.

Al-Mg Alloy Wire
Aluminum is the main element of Al-Mg alloy aluminum wire. A small amount of Mg or other metal materials are added to strengthen the hardness of Al-Mg alloy aluminum wire through smelting, wire drawing processes as well as high-temperature annealing. It will not cause material variation due to mechanical processing or high-temperature heat treatment.