Track irregularity behaviours in electron beam selective melting

Abstract

The random powder particles in additive manufacturing add complexity to the track formation compared to welding. In this paper, the track irregularity in electron beam selective melting of Ti–6Al–4V has been studied with validated high-fidelity multi-physics modelling for an enhancement in understanding the formation mechanisms. It reveals two main mechanisms in track irregularity, necking and fluctuation. It is the powder coalescence behaviour that leads to track fluctuation, and the mitigation of track fluctuation could be ascribed to the melt pool development process. In a multi-layer building process, the track irregularity could increase the possibility of voids generation and development across multilayer, which makes it crucial to explicitly consider the discrete particles for better prediction of build quality.

KEYWORDS:

• Electron beam selective melting
• additive manufacturing
• track irregularity
• formation mechanisms
• build quality
• numerical simulation
• high-fidelity model

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Key R&D Program of China [No. 2017YFB1103300], National Natural Science Foundation of China [No. 51975320] and the Beijing Natural Science Foundation [No. M22011].