Solder Alloy 721 vs. 4115 Aluminum
Solder alloy 721 belongs to the otherwise unclassified metals classification, while 4115 aluminum belongs to the aluminum alloys. There are 22 material properties with values for both materials. Properties with values for just one material (9, in this case) are not shown. Please note that the two materials have significantly dissimilar densities. This means that additional care is required when interpreting the data, because some material properties are based on units of mass, while others are based on units of area or volume.
For each property being compared, the top bar is solder alloy 721 and the bottom bar is 4115 aluminum.
Metric UnitsUS Customary Units
Mechanical Properties
| Elastic (Young's, Tensile) Modulus, GPa | 51 | |
| 70 |
| Elongation at Break, % | 17 | |
| 1.1 to 11 |
| Poisson's Ratio | 0.36 | |
| 0.33 |
| Shear Modulus, GPa | 19 | |
| 26 |
| Tensile Strength: Ultimate (UTS), MPa | 50 | |
| 120 to 220 |
Thermal Properties
| Latent Heat of Fusion, J/g | 61 | |
| 420 |
| Melting Completion (Liquidus), °C | 220 | |
| 640 |
| Melting Onset (Solidus), °C | 210 | |
| 590 |
| Specific Heat Capacity, J/kg-K | 220 | |
| 900 |
| Thermal Conductivity, W/m-K | 56 | |
| 160 |
| Thermal Expansion, µm/m-K | 22 | |
| 23 |
Electrical Properties
| Electrical Conductivity: Equal Volume, % IACS | 14 | |
| 41 |
| Electrical Conductivity: Equal Weight (Specific), % IACS | 17 | |
| 140 |
Otherwise Unclassified Properties
| Density, g/cm3 | 7.4 | |
| 2.7 |
| Embodied Carbon, kg CO2/kg material | 17 | |
| 8.1 |
| Embodied Energy, MJ/kg | 280 | |
| 150 |
Common Calculations
| Stiffness to Weight: Axial, points | 3.8 | |
| 14 |
| Stiffness to Weight: Bending, points | 17 | |
| 50 |
| Strength to Weight: Axial, points | 1.9 | |
| 12 to 23 |
| Strength to Weight: Bending, points | 4.1 | |
| 20 to 30 |
| Thermal Diffusivity, mm2/s | 34 | |
| 66 |
| Thermal Shock Resistance, points | 3.2 | |
| 5.2 to 9.9 |
Alloy Composition
| Aluminum (Al), % | 0 to 0.0010 | |
| 94.6 to 97.4 |
| Antimony (Sb), % | 0 to 0.1 | |
| 0 |
| Arsenic (As), % | 0 to 0.030 | |
| 0 |
| Bismuth (Bi), % | 0.8 to 1.2 | |
| 0 |
| Cadmium (Cd), % | 0 to 0.0020 | |
| 0 |
| Copper (Cu), % | 0.3 to 0.7 | |
| 0.1 to 0.5 |
| Gold (Au), % | 0 to 0.050 | |
| 0 |
| Indium (In), % | 0 to 0.1 | |
| 0 |
| Iron (Fe), % | 0 to 0.020 | |
| 0 to 0.7 |
| Lead (Pb), % | 0 to 0.070 | |
| 0 |
| Magnesium (Mg), % | 0 | |
| 0.1 to 0.5 |
| Manganese (Mn), % | 0 | |
| 0.6 to 1.2 |
| Nickel (Ni), % | 0 to 0.010 | |
| 0 |
| Silicon (Si), % | 0 | |
| 1.8 to 2.2 |
| Silver (Ag), % | 2.3 to 2.7 | |
| 0 |
| Tin (Sn), % | 95 to 96.6 | |
| 0 |
| Zinc (Zn), % | 0 to 0.0010 | |
| 0 to 0.2 |
| Residuals, % | 0 | |
| 0 to 0.15 |