Thermal conductivity against densityHigher and further left: spreads more heat for its weightThermal expansion against thermal conductivityLower and further right: warps less when heated
Try it on a partA sample part to run stress or thermal on, free in your browser
Sources3 documents: Magnesium Elektron, Isola, U.S. Department of Defense
Magnesium AZ91D
ELEKTRON AZ91D magnesium die-casting alloy, as cast; Magnesium Elektron datasheet 475 (7/01), typical properties; Poisson from MIL-HDBK-5J for AZ91C castings.
PCB Board FR-4, 2 copper planes
A whole circuit board read as one orthotropic plate: the JEDEC high-K thermal test board (JESD51-7, "2s2p"), 0.062 in (1.575 mm) thick with two internal solid copper planes 0.0014 in (1 oz) thick, as Texas Instruments SZZA017A Table 1 gives it. Copper C110 and the Isola 370HR laminate from this library; the layers conduct in parallel along the board and in series through it (boardStackup.ts). Its two 0.0028 in trace layers cover little of the board and are left out; vias are ignored. Mechanical values are the bare laminate's.
1
Elektron Die Casting Alloys (Datasheet 475)Magnesium Elektronarchived copyMagnesium AZ91D · Yield strength: typical, 0.2% tensile yield, ambient temperatureMagnesium AZ91D · Ultimate tensile strength: typical, ambient temperatureMagnesium AZ91D · Elongation at break: typical, ambient temperatureMagnesium AZ91D · Young's modulus (stiffness): typicalMagnesium AZ91D · Density: typicalMagnesium AZ91D · Thermal conductivity: typicalMagnesium AZ91D · Thermal expansion: typical, temperature range not statedMagnesium AZ91D · Specific heat: typicalMagnesium AZ91D · Melting point: melting range
2
370HR Laminate and Prepreg Data SheetIsolaarchived copyPCB Board FR-4, 2 copper planes · Ultimate tensile strength: the bare laminate's (fr4-370hr), in-plane: cross direction .. length direction (ASTM D3039)PCB Board FR-4, 2 copper planes · Young's modulus (stiffness): the bare laminate's (fr4-370hr), in-plane: cross direction .. length direction (ASTM D790-15e2); the copper planes are left outPCB Board FR-4, 2 copper planes · Poisson's ratio: the bare laminate's (fr4-370hr), in-plane: cross direction .. length directionPCB Board FR-4, 2 copper planes · Thermal expansion: the bare laminate's (fr4-370hr), in-plane X/Y-axis, below Tg (IPC-TM-650 2.4.24C)
3
MIL-HDBK-5J, Metallic Materials and Elements for Aerospace Vehicle Structures (2003)U.S. Department of DefenseMagnesium AZ91D · Poisson's ratio: base material: AZ91C casting (MIL-HDBK-5J handbook physical constant)
Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Mechanical
Is Magnesium AZ91D stronger than PCB Board FR-4, 2 copper planes?
PCB Board FR-4, 2 copper planes is stronger: its tensile strength is 315 MPa against yield strength 150 MPa for Magnesium AZ91D (2.1x).
Which is stiffer, Magnesium AZ91D or PCB Board FR-4, 2 copper planes?
Magnesium AZ91D is stiffer: Young's modulus 45 GPa against 23.9 GPa for PCB Board FR-4, 2 copper planes, so the same part in Magnesium AZ91D deflects less under the same load.
Thermal
Which expands less with temperature?
PCB Board FR-4, 2 copper planes expands less: 13.5 µm/m·K against 25 µm/m·K for Magnesium AZ91D.