Laser powder bed fusion of an al-mg-sc-zr alloy: Manufacturing, peak hardening response and thermal stability at peak hardness
Artikel i vetenskaplig tidskrift, 2022

This study shows a rapid and systematic approach towards identifying full density and peak hardness for an Al-Mg-Sc-Zr alloy commonly known as Scalmalloy®. The alloy is tailored for the laser powder bed fusion process and has been shown to be printable with >99.8% relative density. The microstructure suggests Al grain refinement in melt pool boundaries, associated with formation of primary Al3 (Sc, Zr) particles during solidification. Peak hardening response was identified by heat treatment tests at 573,598 and 623 K between 0 and 10 h. A peak hardness of 172 HV0.3 at 598 K for 4 h was identified. The mechanical properties were also tested with yield and ultimate strengths of 287 MPa and 364 MPa in as-printed and 468 MPa and 517 MPa in peak hardened conditions, respectively, which is consistent with the literature. Such an approach is considered apt when qualifying new materials in industrial laser powder bed fusion systems. The second part of the study discusses the thermal stability of such alloys post-peak-hardening. One set of samples was peak hardened at the conditions identified before and underwent secondary ageing at three different temperatures of 423,473 and 523 K between 0 and 120 h to understand thermal stability and benchmark against conventional Al alloys. The secondary heat treatments performed at lower temperatures revealed lower deterioration of hardness over ageing times as compared to the datasheets for conventional Al alloys and Scalmalloy®, thus suggesting that longer ageing times are needed.

Aluminium alloys

Additive manufacturing

High temperature performance

High strength

Författare

Bharat Mehta

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Arvid Svanberg

Student vid Chalmers

Lars Nyborg

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Metals

2075-4701 (eISSN)

Vol. 12 1 57

Styrkeområden

Produktion

Ämneskategorier

Bearbetnings-, yt- och fogningsteknik

Annan materialteknik

Metallurgi och metalliska material

DOI

10.3390/met12010057

Mer information

Senast uppdaterat

2022-01-10