Novel drawing system approach to manufacture performant commercially pure aluminium fine wires

Due to its electro-mechanical properties, commercially pure aluminium wires have attracted the interest of automotive industry representing a functional and efficient economic solution to reduce vehicle’s weight leading to the diminishing of energy consumption and emissions in today’s society. However, to consolidate its use in this sector and in new market realities, it is necessary to increase the flexibility of the aluminium conductor wires, consenting their installation in very small spaces and with high curvatures, avoiding any failure and electrical conductivity decrease. Thus, the evolution of microstructure and service performance needs to be investigated and controlled to improve the service safety. The present research shows a new approach to continuously manufacture efficient long wires with smaller diameters and fine grains at room temperature. It is studied the strengthening effects (yield and tensile strength, plasticity, hardness), the electrical conductivity, and the microstructural changes of commercial 1370 pure aluminium (99.7% Al) when traditional wire drawing process is combined with equal channel angular drawing (ECAD) technique. The results of this proposed procedure of deformation “drawing-ECAD-drawing” show an evident benefit, compared to the classic technology of production of aluminium wire, obtaining fine grain structure product with superior mechanical strength and not influenced electrical conductivity. The proposed manufacturing approach leads to fine wires enhancing the material mechanical properties by microstructural evolution (i.e. grain size reduction) avoiding the traditional post manufacturing thermal treatments requiring a high amount of energy and time and careful steps.

Effect of Substrate Alloy Type on the Microstructure of the Substrate and Deposited Material Interface in Aluminium Wire Arc Additive Manufacturing

Wire + Arc Additive Manufacture is an Additive Manufacturing process that requires a substrate to initiate the deposition process. In order to reduce material waste, build and lead time, and improve process efficiency, it is desirable to include this substrate in the final part design. This approach is a valid option only if the interface between the substrate and the deposited metal properties conform to the design specifications. The effect of substrate type on the interface microstructure in an aluminium part was investigated. Microstructure and micro-hardness measurements show the effect of substrate alloy and temper on the interface between the substrate and deposited material. Microcracks in the as-deposited condition were only found in one substrate. The deposited material hardness is always lower than the substrate hardness. However, this difference can be minimised by heat treatment and even eliminated when the substrate and wire are made of the same alloy.

Novel Drawing System Approach To Manufacture Performant Commercially Pure Aluminium Fine Wires

Due to its electro-mechanical properties, commercially pure aluminium wires have attracted the interest of automotive industry representing a functional and efficient economic solution to reduce vehicle’s weight leading to the diminishing of energy consumption and emissions in today’s society. However, to consolidate its use in this sector and in new market realities, it is necessary to increase the flexibility of the aluminium conductor wires, consenting their installation in very small spaces and with high curvatures, avoiding any failure and electrical conductivity decrease. Thus, the evolution of microstructure and service performance need to be investigated and controlled to improve the service safety. The present research shows a new approach to efficiently continuously manufacture long wires with smaller diameters and fine grains at room temperature. It is studied the strengthening effects (yield and tensile strength, plasticity, hardness), the electrical conductivity and the microstructural changes of commercial 1370 pure aluminium (99.7% Al) when traditional wire drawing process is combined with equal channel angular drawing (ECAD) technique. The results of this proposed procedure of deformation “drawing-ECAD-drawing” show an evident benefit, compared to the classic technology of production of aluminium wire, obtaining fine grain structure product with superior mechanical strength and not influenced electrical conductivity. The proposed manufacturing approach leads to fine wires enhancing the material mechanical properties by microstructural evolution (i.e. grain size reduction) avoiding the traditional post manufacturing thermal treatments requiring a high amount of energy and time and careful steps.

Cell Interconnections in Battery Packs Using Laser-assisted Ultrasonic Wire Bonding

This paper presents the results of a series of bonding tests using a laser-assisted ultrasonic wire bonding process. Aluminium and copper wire, both 500 μm (20 mil) thick, were bonded to nickel-coated steel caps of type 21700 battery cells. Mechanical bond strength tests prove that laser-assisted wire bonding has significant advantages over room temperature wire bonding. For example, it can be used to reduce the process time with aluminium wire or to increase the bondability of copper wire on nickel-coated steel. The results show a direct relation between tool tip temperature and measured bond strength. The quality of the joints was effectively improved by heating the tool tip up to 430 °C. These advantages are the same as in classic thermosonic wire bonding, but without the major disadvantage of having to heat to whole package. The cell temperature was shown to remain safely below the critical 60 °C in any application.

Performance of fiber metal laminate composites embedded with AL and CU wire mesh

This work was investigated that the effect of aluminium (Al) and copper (Cu) wire mesh embedded as a structural reinforcement on jute epoxy hybrid composite. The hybrid composites were prepared by epoxy LY556 with HY951 hardener as a matrix; jute and wire mesh as reinforcements using the compression molding technique. In hybrid composites, the aluminium wire mesh (AWM) and copper wire mesh (CWM) were embedded as 45° & 90° orientation to the jute fiber (AWM45/90 and CWM45/90). The performance of the fabricated hybrid composites was studied by conducting various mechanical, thermal, and dynamic characterizations. The test results were shown that the tensile strength of the fabricated composite was improved by 14.12% in AWM45 and 9.28% in CWM45 compared to AWM90 and CWM90 composites respectively. The TGA result expressed that the thermal stability of the CWM45 composite was enhanced with the residue of 18.33% at 800 °C due to the influence of Cu-wire mesh. In the transition region, the 45° oriented wire mesh improved the loss modulus (E″) peaks about 31.74% in CWM and 11.49% in AWM composite to 90° oriented mesh.

Manufacturing Technology of Aluminium Wire from Alloy 01417 with Adjusted Level of Mechanical Properties

In the 70s of the last century, Soviet scientists developed an aluminum alloy with 7% rare earth elements (REE), which at melt cooling speeds of up to 104 deg/s are dispersed into intermetallic phases, which significantly increase the heat resistance, corrosion resistance, and weldability of finished products for conductive material. To ensure melt cooling rates of up to 104 deg/s in those years, centrifugation of granules in water was used. To increase the efficiency of this redistribution, a pilot industrial line was used for continuous pellet pressing by the Conform method. A method has been developed for producing small-section billets (Æ 8-12 mm) with a crushed structure from Al-REM system alloys by continuous casting in electromagnetic crystallizer (EMC) mounted at Magnetic Hydrodynamics Scientific and Production Center LLC. In this method of casting, a dispersed structure is obtained with a slight intra-dendritic segregation, which guarantees a high level of mechanical properties. A series of experiments was carried out on continuous pressing at the Conform installation of a batch of Æ 12 mm rod and drawing it to Æ 0.5 mm wire without annealing. To predict the properties of the wire that meet the requirements of TU 1-809-1038-2018, an experimental plan has been drawn up and implemented to determine the dependence of mechanical properties on the exposure time (τ) and the annealing temperature (t) of the wire. As a result of processing the experimental data, regression equations were obtained and graphs of the dependence temporary tensile strength (σв) and relative elongation (δ) on the temperature and holding time, which can be used when annealing Æ 0.5 mm wire from 01417 alloy to obtain the required mechanical properties

Intelligent Production of Wire Bonds using Multi-Objective Optimization – Insights, Opportunities and Challenges

Ultrasonic wire bonding is an indispensable process in the industrial manufacturing of semiconductor devices. Copper wire is increasingly replacing the well-established aluminium wire because of its superior electrical, thermal and mechanical properties. Copper wire processes differ significantly from aluminium processes and are more sensitive to disturbances, which reduces the range of parameter values suitable for a stable process. Disturbances can be compensated by an adaption of process parameters, but finding suitable parameters manually is difficult and time-consuming. This paper presents a physical model of the ultrasonic wire bonding process including the friction contact between tool and wire. This model yields novel insights into the process. A prototype of a multi-objective optimizing bonding machine (MOBM) is presented. It uses multi-objective optimization, based on the complete process model, to automatically select the best operating point as a compromise of concurrent objectives.