Understanding Metal Additive Manufacturing - 2 — Lesson 2

This lesson covers the characterization and evaluation of parts made through Metal Additive Manufacturing (AM). It delves into the mechanical properties of AM printed parts, including hardness, tensile static strength, and fatigue behavior. The lesson also discusses common defects in AM printed alloys and how porosity affects cracking and mechanical properties. It further explains how the mechanical properties of AM parts can be comparable to conventionally made parts, and how the microstructure can be manipulated using AM techniques. The lesson also highlights the importance of non-destructive testing methods in identifying porosities and ensuring quality. The lesson concludes with a discussion on the impact of different process parameters on the hardness of AM parts.

Video Highlights

00:32 - Discussion on the mechanical properties of additive manufacturing printed parts and hardness of additive manufacture printed alloys
04:50 - Explanation of how inefficient energy flux can cause unmelted materials, resulting in irregular voids and reducing the density
09:14 - Discussion on how the higher densities achievable with additive manufacturing suggest optimization guidelines for additive manufactured parameters to achieve optimum volume energy
15:45 - Discussion on how the hardness of additive manufactured processed ferrous alloy is influenced by process input parameters of additive manufacturing
22:47 - Explanation of how the hardness of LDED-processed austenitic stainless steel as a function of Secondary Dendritic Arm Spacing
32:13 - Discussion on how the hardness of additive manufactured part of aluminium alloy decreases with respect to lath width

Key Takeaways

- Metal Additive Manufacturing allows for the creation of parts with mechanical properties comparable to conventionally made parts.
- Porosity, which can be caused by thermomechanical properties of the metal powder and laser process parameters, affects cracking and mechanical properties.
- Non-destructive testing methods are crucial in identifying porosities and ensuring the quality of AM parts.
- Different process parameters can impact the hardness of AM parts, and post-processing treatments can influence the mechanical properties of these parts.
- The mechanical properties of AM parts can be improved through precipitation hardening and solid solution strengthening.