Are you using this file?
https://github.com/FreeCAD/FreeCAD/blob ... 1-T6.FCMat
There are some issues inside:
; Aluminum-6061-T6
; (c) 2016 Mandeep Singh (CC-BY 3.0)
; Information about the content of such cards you can find here:
; http://www.freecadweb.org/wiki/index.php?title=Material
[FCMat]
Name = Aluminum 6061-T6
Description = Precipitation-hardened, Nonferrous Aluminum alloy
Father = Metal
ProductURL = https://en.wikipedia.org/wiki/6061_aluminium_alloy
YoungsModulus = 69000 MPa
UltimateTensileStrength = 310 MPa
PoissonRatio = 0.33
Density = 2700 kg/m^3
KindOfMaterial = Aluminium
KindOfMaterialDE = Aluminium
ThermalConductivity = 167 W/m/K
After changing red marked units, loading of material works on my side.
tested with:
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13375 (Git)
Build type: Release
Branch: master
Hash: 2bfea410fce1434fec0f853b032549aa2cd3c47e
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0
Locale: German/Germany (de_DE)