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Selective electron beam melting (SEBM) is a highly versatile powder bed fusion additive manufacturing method. SEBM is characterized by high energy densities which can be applied with nearly inertia free beam deflection at high speeds (<8.000 m/s). This paper aims to determine processing maps for Ti-6Al-4V on an Arcam Q10 machine with LaB6 cathode design.

Scan line spacings of 100, 50 and 20 µm in a broad parameter range, focusing on high deflection and build speeds are investigated.

There are broad processing windows for dense parts without surface flaws for all scan line spacings which are defined by the total energy input and the area melting velocity.

The differences and limitations are discussed taking into account the beam properties at high beam energy and velocity as well as evaporation related loss of alloying components.

The purpose of this study is the introduction and validation of a new technique for process monitoring during electron beam melting (EBM).

In this study, a backscatter electron detector inside the building chamber is used for image acquisition during EBM process. By systematic variation of process parameters, the ability of displaying different topographies, especially pores, is investigated. The results are evaluated in terms of porosity and compared with optical microscopy and X-ray computed tomography.

The method is capable of detecting major flaws (e.g. pores) and gives information about the quality of the resulting component.

Image acquisition by evaluating backscatter electrons during EBM process is a new approach in process monitoring which avoids disadvantages restricting previously investigated techniques.

The purpose of this paper is to investigate the possibility of in situ flaw detection for powder bed, beam‐based additive manufacturing processes using a thermal imaging system.

The authors compare infrared images (IR) which were taken during the generation of Ti‐6Al‐4V parts in a selective electron beam melting system (SEBM) with metallographic images taken from destructive material investigation.

A good match is found between the IR images and the material flaws detected by metallographic techniques.

First results are presented here, mechanisms of flaw formation and transfer between build layers are not addressed in detail.

This work has important implications for quality assurance in SEBM and rapid manufacturing in general.

This study aims to provide a comprehensive overview of the current state of the art in powder bed fusion (PBF) techniques for additive manufacturing of multiple materials. It reviews the emerging technologies in PBF multimaterial printing and summarizes the latest simulation approaches for modeling them. The topic of “multimaterial PBF techniques” is still very new, undeveloped, and of interest to academia and industry on many levels.

This is a review paper. The study approach was to carefully search for and investigate notable works and peer-reviewed publications concerning multimaterial three-dimensional printing using PBF techniques. The current methodologies, as well as their advantages and disadvantages, are cross-compared through a systematic review.

The results show that the development of multimaterial PBF techniques is still in its infancy as many fundamental “research” questions have yet to be addressed before production. Experimentation has many limitations and is costly; therefore, modeling and simulation can be very helpful and is, of course, possible; however, it is heavily dependent on the material data and computational power, so it needs further development in future studies.

This work investigates the multimaterial PBF techniques and discusses the novel printing methods with practical examples. Our literature survey revealed that the number of accounts on the predictive modeling of stresses and optimizing laser scan strategies in multimaterial PBF is low with a (very) limited range of applications. To facilitate future developments in this direction, the key information of the simulation efforts and the state-of-the-art computational models of multimaterial PBF are provided.

This paper aims to study the effect of processing parameters and the fundamental mechanism of surface morphologies during electron beam selective melting.

From the powder-scale level, first, the discrete element method is used to obtain the powder bed distribution that is comparable with the practical condition; then, the finite volume method is used to simulate the particle melting and flowing process. A physically reliable energy distribution of the electron beam is applied and the volume of fluid method is coupled to capture the free boundary flow. Twelve sets of parameters grouped into three categories are examined, focusing on the effect of scan speed, input powder and energy density.

According to the results, both melting pool width and depth have a positive relation with the energy density, whereas the melting pool length is insensitive to the scan velocity change. The balling effect is attributed to either an insufficient energy input or the flow instability; the hump effect originates from the mismatch between electron beam moving and the fluid flow. The scan speed is a key parameter closely related to melting pool size and surface morphologies.

Through a number of case studies, this paper gives a comprehensive insight of the parameter effects and mechanisms of different surface morphologies, which helps to better control the manufacturing quality of electron beam selective melting.