Metallic microstructure in librecad

I would like to make a hatch with metallic polycristalline microstructure i.e. displaying grains and grain boundary in librecad or any opensource cad. Anyone can help.
Is there any dxf file for this feature?

Thank you in advance

Welcom eli!

The hatch patterns are part of any LibreCAD installation. Where they are located depends on your OS and version.

You can also download them from the source repository here:
https://github.com/LibreCAD/LibreCAD/tree/master/librecad/support/patterns

Basically patterns in LibreCAD are regular DXF files. A pattern is defined in a 100x100 rectangle, which is repeated in any direction for infinite size.
Thus you have to take care, that lines ending on top or right side are continued on the opposite bottom or left side. This can be tricky.

I recommend to create a new pattern DXF in your preferred location and add the path to Hatch Pattern settings in Application Preferences. Probably you have to restart LibreCAD to apply the new location and pattern file to the hatch pattern list.
When your pattern(s) are available, you can modify them for best results. Be aware to use a big enough rectangle or whatever shape to test the pattern, that it is multiplied and the transitions are visible.

You will understand this, when you have a look at the different pattern files and get your hands dirty with your own patterns.
Good luck ;)

Armin