Work Item
ASTM WK85661
New Test Method for Additive Manufacturing -- procedure and coupon geometry -- distortion and residual stresses assessment of Additively Manufactured parts
1. Scope
The Laser-based Powder Bed Fusion of Metals (PBF-LB/M) process features highly dynamic temperature cycles with correspondingly large temperature gradients, which ultimately leads to large internal stresses in the manufactured components. For the systematic determination of the internal stresses and the resulting distortion, cantilever coupons are often manufactured, and the distortion is measured. Although this method has been used for several years in industry as well as in research applications, there is still no standardized measurement methodology or guidelines for the design of cantilever test coupons. There is also a lack of knowledge on how to transfer the results of cantilever tests to application-oriented part geometries. Within the scope of this project, the influences of the cantilever coupon design, the influence of machine, material and heat treatment as well as the applied measurement method will be systematically investigated. Based on the results, a design and test method for the assessment of residual stress will be derived. Similar to national and international standards for the determination of mechanical properties and the design of the corresponding coupon, it should be possible to determine distortion as a decisive quality parameter for PBF-LB/M production using a standardized method.
Keywords
AM; Geometry consistency; part deformation; residual stress modeling; residual stress geometry for AM
Rationale
The Laser-based Powder Bed Fusion of Metals (PBF-LB/M) process features highly dynamic temperature cycles with correspondingly large temperature gradients, which ultimately leads to large internal stresses in the manufactured components. For the systematic determination of the internal stresses and the resulting distortion, cantilever coupons are often manufactured, and the distortion is measured. Although this method has been used for several years in industry as well as in research applications, there is still no standardized measurement methodology or guidelines for the design of cantilever test coupons. There is also a lack of knowledge on how to transfer the results of cantilever tests to application-oriented part geometries.
The title and scope are in draft form and are under development within this ASTM Committee.
Work Item Status
Date Initiated: 03-16-2023
Technical Contact: Alireza Jam
Item: 000
Ballot:
Status: