Experimental Study on Hybrid Additive and Subtractive Manufacturing Processes for Improving Surface Quality

Area of Science:

• Manufacturing Engineering
• Materials Science
• Additive Manufacturing

Background:

• Hybrid machining integrates additive manufacturing (AM) with subtractive processes to overcome AM limitations.
• This approach enables the production of high-precision components with improved surface quality.
• Polyethylene terephthalate glycol (PETG) is a versatile material suitable for 3D printing complex geometries.

Purpose of the Study:

• To investigate the impact of fused deposition modelling (FDM) printing parameters and milling tools on surface roughness of PETG parts.
• To determine optimal hybrid machining strategies for achieving specific surface roughness values.
• To establish predictive relationships between printing, cutting, and milling parameters for PETG.

Main Methods:

• PETG samples were printed using FDM with varying layer heights (0.1 mm, 0.2 mm) and feed rates (90–120 mm/s).
• Surface roughness, topography, and Abbott-Firestone curves were analyzed using a profilometer.
• Grooves were machined using a milling machine with different tools (rotary burr, spiral burr cutter, endmill).
• Microstructure analysis was performed using an inverted microscope.

Main Results:

• Hybrid machining with a layer height of 0.1 mm, feed rate of 120 mm/s, and a rotary burr cutter achieved the lowest surface roughness (Ra = 1.54 μm).
• Specific combinations of printing and machining parameters significantly influence surface roughness outcomes.
• The study identified correlations between printing parameters, milling tools, and achievable surface roughness.

Conclusions:

• Hybrid machining offers a viable method for producing low-roughness PETG components.
• The findings provide a basis for optimizing hybrid machining processes for similar materials.
• Predictive models can be developed to guide parameter selection for desired surface finish in 3D printed and machined parts.