Processability and interfacial characteristics in PBF-LB/M-processed nano-B4C/AlSi10Mg composites with superior high-temperature mechanical performance

Materials Science and Engineering A, vol. 954, pp. 149838

Abstract

Incorporating nano-scaled ceramic particles into additively manufactured Al-alloys is a validated strategy to simultaneously enhance the elevated-temperature mechanical properties and laser powder bed fusion (PBF-LB/M) processability. While B 4 C exhibits outstanding thermal stability and interfacial compatibility with Al, the integration of nano-B 4 C into Al alloys through PBF-LB/M remains insufficiently investigated. In particular, the underlying mechanisms governing laser-particle interaction, processability, and the consequent microstructural formation have not been comprehensively explored. This study aims to address this gap by investigating the effect of nano-B 4 C additions (1, 3, and 5 wt.%) to AlSi10Mg on PBF-LB/M processability and the alloy behavior. The results demonstrated excellent PBF-LB/M processability of the B 4 C/AlSi10Mg composites at all weight fractions of B 4 C. The as-built B 4 C/AlSi10Mg revealed a remarkable columnar-to-equiaxed transition, featuring an ultrafine grain structure (as small as 1.23 μm) with almost random crystallographic texture. This grain refinement was attributed to a reactive nucleation process, where the interfacial reaction between B 4 C and the matrix results in the coherent AlB 2 core-shell structured phase. Furthermore, this interfacial reaction induced a novel morphological transition, characterized by the spheroidization of irregularly shaped nanoparticles as a consequence of partial reactive melting. The B 4 C nanocomposites exhibited superior elevated-temperature mechanical properties, increasing tensile strength by up to 60% compared to their AlSi10Mg counterparts. This study provides fundamental insights into the design and PBF-LB/M processing of Al-based metal-matrix nanocomposites (AMMNCs) for high-temperature applications. • Nano-B 4 C/AlSi10Mg shows superior PBF-LB/M processability, including 5 wt.% B 4 C conditions. • Reactive nucleation stimulates a full columnar-to-equiaxed grain transition. • Irregularly shaped nano-B 4 C undergoes spheroidization induced by partial reactive melting. • Melt pool evolution is altered by several counteracting heat transfer mechanisms. • Tensile strength at 300 °C increases by 60% over AlSi10Mg while maintaining 11% total elongation.

Authors 7

1. Abdelrahman Elsayed corresponding Aachen IEHK Steel Institute

   Suez University · RWTH Aachen University

   Affiliation as printed

   Department of Metallurgical and Materials Engineering, Suez University, 43528, Suez, Egypt

   IEHK Steel Institute, RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany

2. Ivo Šulák

   Czech Academy of Sciences, Institute of Physics of Materials

   Affiliation as printed

   Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, 616 00 Brno, Czech Republic

3. Frederike Brasche

   Technische Universität Berlin

   Affiliation as printed

   Chair Materials for Additive Manufacturing, TU Berlin, Ernst-Reuter-Platz 1, 10587, Berlin, Germany

4. Tarek Allam

   Suez University · Forschungszentrum Jülich

   Affiliation as printed

   Department of Metallurgical and Materials Engineering, Suez University, 43528, Suez, Egypt

   Institute of Energy Materials and Devices: Microstructure and Properties of Materials (IMD-1), Research Center Jülich, 52428, Jülich, Germany

5. Marion Kreins Aachen IEHK Steel Institute

   RWTH Aachen University

   Affiliation as printed

   IEHK Steel Institute, RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany

6. Ulrich Krupp Aachen IEHK Steel Institute

   RWTH Aachen University

   Affiliation as printed

   IEHK Steel Institute, RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany

7. Christian Haase

   Technische Universität Berlin

   Affiliation as printed

   Center for 3D Technologies, TU Berlin, Straße des 17. Juni 136, 10623, Berlin, Germany

   Chair Materials for Additive Manufacturing, TU Berlin, Ernst-Reuter-Platz 1, 10587, Berlin, Germany