Laser Powder Bed Fusion of Chromium Bronze Using Recycled Powder

Ivan A Pelevin,Stanislav V Chernyshikhin,Alexander S Shinkaryov,Alexander A Gromov,Dmitriy Yu Ozherelkov,Anton Yu Nalivaiko,Maxim A Burmistrov

doi:10.3390/ma14133644

Abstract

Laser powder bed fusion (LPBF) of Cu-0.5Cr was carried out using recycled powder taken out from the LPBF machine after previous printing. Various volumetric defects characterized the powder wherein particle size distribution was the same as virgin powder. Using recycled powder resulted in extra spherical pore formation after the LPBF process. Despite that, a relative density of 99.2% was achieved by LPBF parameters optimization. Solidified microstructure with a small volume of defects consisted of an oversaturated dendritic Cu matrix and nano-sized Cr precipitations providing strengthening mechanism occurrence. The possibility of a satisfactory level of mechanical properties with σ0.2 = 136.8 MPa, UTS = 187.4 MPa, along with 15.5% of elongation achieving, was shown.

Highlights

Such ancient material as bronze is still used nowadays in various industries due to its physical and mechanical properties [1]
Laser powder bed fusion of chromium bronze with 0.5 mass.% was successfully performed using a recycled powder that was not used in the previous LPBF process, taken from the machine, and sieved to reject large particles
The formation of an almost defect-free microstructure consisted of fine copper dendritic matrix oversaturated by chromium with nano-sized chromium precipitations due to rapid solidification during the LPBF process

Summary

Introduction

Such ancient material as bronze is still used nowadays in various industries due to its physical and mechanical properties [1]. Dobatkin et al [30] used severe plastic deformation to form ultrafinegrained microstructures in Cu–Cr alloys to obtain high material strength and good electrical conductivity. Study of Cu–Cr alloy microstructure, electrical and mechanical properties after LPBF was performed only by Uchida et al [31]. The LPBF procedure implies less material waste than substractive methods, but reasonable consumption arises when unmelted powder that did not take part in the building is not used in subsequent syntheses Usage of such recycled powder provides a decrease of the whole LPBF process costs but needs the particular focus of researchers to study this powder applicability. A comparative analysis of the mechanical behavior of the Cu-0.5Cr bronze synthesized using recycled and virgin powder based on experimental data from [36] was performed

Materials and Methods

Discussion

Cross-section

Conclusions