Part-Support Configuration Assessment of a Wheel-Bearing Structure

Look at the image above; in your opinion, which Part-Support configuration will experience the LEAST deformation of the final Part.

More info in regard to the Part-Support configuration:

- Part: wheel bearing structure

- Support: Predominantly cone supports

- Material: Ti6Al4V

- AM process: LPBF

- Deformation of the final Part: The deformation that occurs once the configuration is removed from the building plate and the Supports are removed from the Part.

Recently we published a post asking metal AM enthusiasts their opinion about three Part-Support configurations (A, B or C) and which one would show the least deformation upon Building-plate and Support removal. We performed a metal AM process simulation via the Inherent Strain method and concluded the correct answer is the configuration C. The configuration C shows the least local deformations as well as the least overall global deformations.

We counted the answers from the poll of this post and concluded the following distribution in answers: 22% voted for A, 25% voted for B, and 53% voted for C, thus, the majority guessed the correct answer and identified the Part-Support configuration C as the one showing the least deformation. (Note: the votes were counted on 28 May 2022)

But let's back up a little and address some valid comments that were brought up in the poll:

1. Uniformity of the central ring structure: Comments were raised about whether the shape of the central ring structure matters. We did not specify this in detail in the original post. However, if one wants to ensure the cylindricity of the central Part feature, e.g. to avoid post processing, the configuration A may become a more suitable candidate.

2. Concerns about processing times: Due to the considerable lower build-height of configurations A and B, they would potentially allow more cost-efficient manufacturing due to reduced processing times. Keeping the manufacturing costs low is often a very important criteria that may outweigh achieving better geometrical tolerances.

3. Usage of excessive Support material: The configurations B and C utilized considerable more Support material (> +33%) compared to A. This would in addition to the increased build-hight and subsequent increased manufacturing costs favor scenario A if occurring deformations are of lesser importance.

4. Balancing the heat-flow during the process: Managing the heat during the metal AM process is a very important aspect which has a significant impact on the final material quality and Part performance. Managing uniform thermal gradients throughout the entire building process is key to generating high quality parts as described in this post. While we did not perform a thermal analysis on the configurations within the framework of this publishing, we agree with the comments stating that configuration C may be more beneficial to maintain uniform thermal gradients.

5. Heat treatment: Even though we did not consider heat treatment in this simulation, our experience is that procedures such as HIP can considerably relieve residual stresses and subsequently reduce the overall deformations.