​Effect of the thermal distortion on the component geometry.​
​Image credit: Eduard Hryha, Chalmers

Optimization of the AM components properties by post-manufacturing treatment

We want to establish a design and simulation platform for selection of the optimized post-treatment procedure in dependence on material/alloy and AM technique applied. This includes mapping of different post-treatment techniques for different types of alloys, establishment of their effect on the material performance as well as cost-effectiveness. 

Post-treatment is typically the must in powder bed AM, starting from the removal of the support structures, annealing to remove residual stresses and minimize distortions, improve surface finish, minimize numbers and size of the critical defects as lack of fusion and porosity, improve mechanical properties by heat treatment, etc. 

Research will focus on three main directions: 
  • Establishment of the effective heat-treatment (including HIP) protocols, 
  • Robust surface treatment processes to increase dynamic properties of the components as well as corrosion resistance, 
  • Machining protocols for robust removal of the support structures as well as fine machining of the functional surfaces.

Image above: Cut section of Shell structure with powders after EBM fabrication (left), after HIP (middle) and the micrograph of the interface region between shell and powders after HIP (right).

Five initiatives

​In each research area there are specific ongoing initiatives. In this area, there are five:​

  1. Tailored heat treatment to optimize AM materials properties
    Post-manufacturing treatment is typically required in order to relieve the stresses, especially important in case of laser sintering, as well as to optimize microstructure. This is usually done by heat treatment procedures, recipes of which are transferred from traditional metallurgy for AM manufactured components. Classical heat treatment processes have to be re-considered to take into account initial state of the as-manufactured AM microstructure. High-performance AM components are typically hot isostatic pressed (HIP) in order to minimize defects such as residual porosity, lack of fusion, etc. Also a novel HIP cycle that includes heat treatment in one process will be applied.
  2. Local heat treatment for LMD of superalloy structures
    Focus is on AM of Nickel-based superalloys, involving both powder bed and direct metal deposition techniques and on adopting local heat treatments for pre- and post-build processing. The ability of different local post-heat treatment schedules to locally modify properties of LMD superalloy builds will be evaluated. The influence of various pre-heat treatment protocols on properties of LMD superalloy builds will also be investigated. Both simulation using Gleeble and actual experiments employing a new portable local induction facility are envisioned. 
  3. Robust surface treatment processes to optimize AM materials properties
    Focus is placed on the optimization of the surface properties, i.e. the minimization of the surface roughness of the AM components in dependence on process used, process parameters applied as well as base powder characteristic (in collaboration with RA1). High surface roughness of the AM components affects dynamic properties of the parts and hence application requiring improved fatigue performance requires improvement of the surface finish. Focus is also placed on the increased corrosion resistance of AM components that will be selected in dependence on material and application (e.g. by anodization or surface coatings).
  4. Robust machining process for AM
    Development of robust machining procedures for efficient removal of the support structures is one of the key prerequisites required for the AM process integration in the manufacturing chain and full process automation. Hence, optimization of the support structures in close collaboration with the RA1 will be performed in order to be able to optimize support structures removal already at the design stage. Machining guidelines will be provided in dependence on material and surface properties required. Fine machining will also be applied in order to improve the surface properties of the AM manufactured components. 
  5. Tailoring design and mechanical properties of AM manufactured implants for improved biological response
    This subproject aims at elucidating the relationship between the design, bulk material and manufacturing parameters and its related mechanical properties with the biological response and function in bone anchoring application. In addition, post-manufacturing processes for altering the surface properties are developed for further improving the healing kinetics and bone formation.

Research Area Leaders

Prof. Uta Klement,​ Chalmers and Anders Eklund, Quintus Technologies

Researchers involved

Suhas Sreekant, PhD student, University West
Magnus Kahlin (Saab) – industrial PhD student, Linköping University (defended 2021)
Prof. Uta Klement, Chalmers
Prof. Eduard Hryha, Chalmers
Prof. Peter Krajnik, Chalmers
Prof. Johan Moverare, Linköping University 
Prof. Shrikant Joshi, University West
Assoc. Prof. Anders Palmquist, Gothenburg University

Partners involved

Linköping University, University West, SAAB, Volvo GTO, Volvo Cars, Sandvik, Arcam, Siemens, Atlas Copco, AGA Gas, GKN, Quintus Technologies, RZ Riboverken, Brogrens, AIM Sweden, Tooltec, Lasertech, Modul Systems

Page manager Published: Mon 28 Feb 2022.