While Illustrator cannot save as DXF it allows you to export your file ... Illustrator you would have to first convert it to an AI file in CorelDraw then you will be able to open it with Illustrator.

Bear File Converter is useful if you want the DXF file to be in the STL file format. It's an online converter. dxf2gcode can save a DXF file to the G-CODE for Linux CNC format with the NGC file ...