iv to iges conversion seems to represent a transformation of 3D models from SGI Invertor 3D format (.iv) to IGES format (.igs, .iges). You can find several programs that allow this particular extension, especially those that support export for 3D printers.
Open IV file Open IGES file3D viewer and converter with huge file type support
A CAD viewer program with conversion capabilities
A 3D CAD translation software