Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity

Version 1 : Received: 23 April 2023 / Approved: 24 April 2023 / Online: 24 April 2023 (11:19:12 CEST)

A peer-reviewed article of this Preprint also exists.

Mukherjee, S.; Dhara, S.; Saha, P. Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity. Bioengineering 2023, 10, 675. Mukherjee, S.; Dhara, S.; Saha, P. Design and Additive Manufacturing of Acetabular Implant with Continuously Graded Porosity. Bioengineering 2023, 10, 675.

Abstract

Porous structured metallic implants are preferable as bone graft substitutes due to their faster tissue integration mediated by bone in-growth and vascularization. The porous scaffolds/ implants should also mimic the graded structure of natural bone to ensure a match of mechanical properties. This article presents a method to design graded porous structured acetabular implant and identifies the suitable parameters for manufacturing the model through additive manufacturing. The design method is based on slice-wise modification to ensure continuity of gradation. Modification of the slices was achieved through the binary image processing route. A geodesic dome type design was adopted for developing the acetabular cup model from the graded porous structure. The model had a solid shell with the target porosity and pore size gradually changing from 65% and 950 µm, respectively, in the inner side to 75% and 650 µm, respectively, towards the periphery. The required dimensions of the unit structures, and the combinations of pore structure and strut diameter to obtain the target porosity and pore size were determined analytically. Suitable process parameters were identified to manufacture the model by Direct Metal Laser Sintering (DMLS) using Ti6Al4V powder after carrying out a detailed experimental study to minimize the variation of surface roughness and warping over different build angles of the strut structures. A dual contour scanning was implemented to simplify the scan strategy. The minimum diameter of struts that could be manufactured using the selected scanning strategy and scanning parameters was found to be 375 µm. Finally, the model was built and from the micro-CT data, the porosities and pore sizes were found to be closely conforming to the designed values. The stiffness of the structures, as found from compression testing, was also found to be well matching with that of human trabecular bone. Further, the structure exhibited compliant bending-dominated behavior under compressive loading.

Keywords

Additive Manufacturing; Graded Porosity; Acetabular Cup; Ti6Al4V; DMLS

Subject

Engineering, Industrial and Manufacturing Engineering

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.