Finite Element Modelling and Validation of Thermomechanical Behaviour for Layered Aluminium Parts Made by Composite Metal Foil Manufacturing

Abstract

The paper presents finite element modelling and thermomechanical analysis on the tensile properties of layered aluminium 1050 metal foil parts made by composite metal foil manufacturing. In this paper, a three-dimensional finite element model was developed and validated through experiments to analyse thermal effects on the tensile properties of 200-μm-thick aluminium 1050 metal foils. The effects of thermal stress and strain were studied by carrying out transient thermal analysis on the heated plates used to join the 200-μm-thick metal foils together using a special brazing paste. A standard tensile test at ambient temperature was carried out on the resulting layered dog bone specimens to analyse the thermal effects on the individual layers of metal. The investigations were precisely designed to assess the effect of heat provided amid the brazing operation to join the metal thwarts together as a layered structure and whether it assumed a part in affecting the tensile properties of the final products when contrasted to a solid aluminium 1050 dog bone specimen of the same dimensions. Corrosion testing was also carried out on dog bone specimens made from varying thickness foils (50 μm, 100 μm, and 200 μm) of aluminium 1050 to assess the effect of corrosion on the tensile strength and elongation. The results showed that the specimens did not face the problem of galvanic corrosion of the foil–bond interface. Microstructural analysis was also carried out to analyse the fracture modes of the tested specimens after corrosion testing.

Finite Element Modeling and Mechanical Testing of Metal Composites Made by Composite Metal Foil Manufacturing

“…It will always be the metal with the most negative anodic index which will ultimately suffer from corrosion when galvanic incompatibility is in play. The results obtained here are also in-line with our previous work with other composites made by CMFM but tested for only 24 h [19,26]. However, it is recommended that longer tests are carried out possibly spanning a month or three months to assess the integrity of the bond/foil interface as after 7 days, it has been concluded that galvanic corrosion does not adversely affect the composites made by CMFM.…”

“…This experiment validated the applicability of numerical simulations to produce parts using CMFM. This result is in-line with the comparison done in our previous work where aluminum foils of 200-micron thickness were utilized [26]. This clearly demonstrate that numerical analysis can be utilized for producing composites using CMFM with different foil thicknesses and geometries.…”

“…The foils have been bonded together with 80% zinc and 20% aluminum by weight brazing paste with non-corrosive flux. The melting point of the brazing paste ranges between 410-470 • C. The paste is deposited on the foils with a layer thickness of 100-micron to ensure consistent thickness of the resulting composites [3,14,26].…”

“…The reason for doing that was to allow for a gradual increase in temperature from one end of the product rather than rapid heating from both sides in a small amount of time. Large/thicker parts with a thickness over 5 mm should be processed with both plates, but for anything less than 3 mm, it is recommended to use only one plate [7,8,14,26]. Excessive heating could result in inadequate bonding due to flux being burned off quickly and pitting of the foils leading to thermal stresses or undesired change in material properties.…”

“…In Equation 1 As evident from Figure 4, the temperature was higher in the middle as compared to the sides, because the specimen to be heated was placed there. The simulation was run for 30 s for this rectangular composite with 5 aluminum layers (made from 500-micron-thick foils) as compared to 40 s for a 10 aluminum layered composite (using 200-micron-thick aluminum foils) used in our previous work with a dog-bone geometry [26]. The reason is that there are less layers to braze/join in the current work (only 5 compared to 10) which has led to the top foil of aluminum (adjacent to the OFF plate) reaching 410 °C (operating range for the brazing paste is 410-470 °C) after 10 s. Since bond integrity is a function of the processing time, therefore, to ensure a strong bond, a shorter brazing cycle with fast heat-up and a very short holding time at maximum temperature was utilized [32].…”