Contact-Free Support Structures for the Direct Metal Laser Melting Process

Area of Science:

• Materials Science
• Mechanical Engineering
• Additive Manufacturing

Background:

• Direct Metal Laser Melting (DMLM) offers design freedom but requires support structures for overhangs.
• Current support removal is costly, time-consuming, and can damage components.
• Contact-free supports present a novel alternative to traditional support methods.

Purpose of the Study:

• To investigate the feasibility of contact-free supports in DMLM.
• To analyze the impact of gap distance and overhang inclination angle on surface topography and microstructure.
• To evaluate the effectiveness of contact-free supports for CoCrMo alloy.

Main Methods:

• Preparation of DMLM coupons with contact-free supports using CoCrMo alloy powder.
• Systematic variation of gap distance and overhang inclination angle.
• Characterization using visual inspection, focus variation method for roughness (Ra, Rq, Rz), and optical microscopy.

Main Results:

• Contact-free supports positively influence surface roughness at various build angles.
• Optimal gap distance is critical to prevent powder sintering or loss of support effect.
• Surface topography and sub-surface microstructure are affected by gap distance and inclination angle.

Conclusions:

• Contact-free supports are feasible for DMLM, offering reduced surface roughness.
• Careful control of the gap distance is essential for successful implementation.
• This approach can potentially streamline the additive manufacturing post-processing steps.