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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.

The purpose of this paper is the microstructural and mechanical characterization of a biomedical Ti‐6Al‐4V alloy produced by electron beam melting, and the study of the stability of the as‐built microstructure upon heat treatment.

Ti‐6Al‐4V alloy produced by electron beam melting has been mechanically characterized through tensile and fatigue testing. Its microstructure has been investigated by optical observation after etching and by X‐ray diffractometry analysis. The stability of the microstructure of the as‐built material has been deepened carrying out suitable heat treatments, after an analysis by dilatometry test.

The microstructure of a Ti‐6Al‐4V alloy produced by electron beam melting has a very fine and acicular morphology, because of the intrinsically high‐solidification rate of the process. This microstructure is very stable, and the traditional thermal treatments cannot modify it; the microstructure changes significantly only when an amount of strain is introduced in the material. However, the mechanical properties of the alloy produced by electron beam melting are good.

The paper provides evidence of the microstructural stability of the material produced by electron beam melting. Even if the microstructure of the as‐built material is not recommended by the specific ISO standard, the related mechanical properties are fully satisfactory. This is a significant indication from the point of view of the production of Ti‐6Al‐4V orthopaedic and dental prostheses by electron beam melting.

The purpose of this paper is to investigate the potential application of electron beam melting, as a layered manufacturing process, to fabricate dental coping of metal‐ceramic crown restoration using Ti6Al4V powder.

This experiment was conducted in two steps: shrinkage study to determine scale up factor for shrinkage compensation and parameter selection study, based on thickness, hardness, and surface roughness, to select process parameter of electron beam melting.

A promising result of fabricating metal coping of Ti6Al4V via electron beam melting was shown. Ti6Al4V coping was successfully fabricated, with an average thickness of 0.52 mm required for dental coping. Total average hardness of 333.35 HV that is comparable to casted Ti6Al4V with considerably high roughness of RSm of 382 μm.

The paper presents a novel application of electron beam melting to fabricate metal coping for metal‐ceramic crown restoration.

The purpose of this paper is to verify the feasibility and evaluate the compressive properties of Ti6Al4V implants with controlled porosity via electron beam melting process. This process might be a promising method to fabricate orthopedic implants with suitable pore architecture and matched mechanical properties.

Ti6Al4V implants with controlled porosity are produced using an electron beam melting machine. A scanning electron microscope is utilized to examine the macro‐pore structures of the Ti6Al4V implants. The compressive test is performed to investigate the mechanical properties of the porous implants.

The fabricated samples show a fully interconnected open‐pore network. The compressive yield strength of the Ti6Al4V implants with the porosity of around 51 percent is higher than that of human cortical bone. The Young's modulus of the implants is similar to that of cortical bone.

The surface of samples produced by electron beam melting process is covered with loosely spherical metal particles. Polishing and ultrasonic cleaning have to be used to remove the loose remnants.

This paper presents the potential application in the fabrication of orthopedic or dental implants using electron beam melting process.

Human aging is becoming a common issue these days as it results in orthopaedic-related issues such as joints disorderness, bone-fracture. People with age = 60 years suffer more from these aforesaid issues. It is expected that these issues in human beings will ultimately reach 2.1 billion by 2050 worldwide. Furthermore, the increase in traffic accidents in young people throughout the world has significantly emerged the need for artificial implants. Their implantation can act as a substitute for fractured bones or disordered joints. Therefore, this study aims to focus on electron beam melted titanium (Ti)-based orthopaedic implants along with their recent trends in the field.

The main contents of this work include the basic theme and background of the metal-based additive manufacturing, different implant materials specifically Ti alloys and their classification based on crystallographic transus temperature (including α, metastable β, β and α + β phases), details of electron beam melting (EBM) concerning its process physics, various control variables and performance characteristics of EBMed Ti alloys in orthopaedic and orthodontic implants, applications of EBMed Ti alloys in various load-bearing implants, different challenges associated with the EBMed Ti-based implants along with their possible solutions. Recent trends and shortfalls have also been described at the end.

EBM is getting significant attention in medical implants because of its minor issues as compared to conventional fabrication practices such as Ti casting and possesses a significant research potential to fabricate various medical implants. The elastic modulus and strength of EBMed ß Ti-alloys such as 24Nb-4Zr-8Sn and Ti-33Nb-4Sn are superior compared to conventional Ti for orthopaedic implants. Beta Ti alloys processed by EBM have near bone elastic modulus (approximately 35–50 GPa) along with improved tribo-mechanical performance involving mechanical strength, wear and corrosion resistance, along with biocompatibility for implants.

Advances in EBM have opened the gateway Ti alloys in the biomedical field explicitly ß-alloys because of their unique biocompatibility, bioactivity along with improved tribo-mechanical performance. Less significant work is available on the EBM of Ti alloys in orthopaedic and orthodontic implants. This study is directed solely on the EBM of medical Ti alloys in medical sectors to explore their different aspects for future research opportunities.

Electron beam melting (EBM) is one of the potential additive manufacturing technologies to fabricate aero-engine components from gamma titanium aluminide (γ-TiAl) alloys. When a new material system has to be taken in to the fold of EBM, which is a highly complex process, it is essential to understand the effect of process parameters on the final quality of parts. This paper aims to understand the effect of melting parameters on top surface quality and density of EBM manufactured parts. This investigation would accelerate EBM process development for newer alloys.

Central composite design approach was used to design the experiments. In total, 50 specimens were built in EBM with different melt theme settings. The parameters varied were surface temperature, beam current, beam focus offset, line offset and beam speed. Density and surface roughness were selected as responses in the qualifying step of the parts. After identifying the parameters which were statistically significant, possible reasons were analyzed from the perspective of the EBM process.

The internal porosity and surface roughness were correlated to the process settings. Important ones among the parameters are beam focus offset, line offset and beam speed. By jointly deciding the total amount of energy input for each layer, these three parameters played a critical role in internal flaw generation and surface evolution.

The range selected for each parameter is applicable, in particular, to γ-TiAl alloy. For any other alloy, the settings range has to be suitably adapted depending on physical properties such as melting point, thermal conductivity and thermal expansion co-efficient.

This paper demonstrates how melt theme parameters have to be understood in the EBM process. By adopting a similar strategy, an optimum window of settings that give best consolidation of powder and better surface characteristics can be identified whenever a new material is being investigated for EBM. This work gives researchers insights into EBM process and speeds up EBM adoption by aerospace industry to produce critical engine parts from γ-TiAl alloy.

This work is one of the first attempts to systematically carry out a number of experiments and to evaluate the effect of melt parameters for producing γ-TiAl parts by the EBM process. Its conclusions would be of value to additive manufacturing researchers working on γ-TiAl by EBM process.

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 paper is to correct the beam deflection errors and beam defocus by using a digital scanning system. Electron beam selective melting (EBSM) is an additive manufacturing technology for metal parts. Beam deflection errors and beam defocus at large deflection angles would greatly influence the accuracy of the built parts.

The 200 × 200 mm2 scanning area of the electron beam is discretized into 1001 × 1001 points arranged in array, based on which a digital scanning system is developed. To correct the deflection errors, the electron beam scans a 41 × 41 testing grid, and the corrective algorithm is based on the bilinear transformation from the grid points’ nominal coordinates to their measured coordinates. The beam defocus is corrected by a dynamic focusing method. A three-dimensional testing part is built with and without using the corrective algorithm, and their accuracies are quantitatively compared.

The testing grid scanning result shows that the accuracy of the corrected beam deflection system is better than ± 0.2 mm and beam defocus at large deflection angles is eliminated visibly. The testing part built with using the corrective algorithm is of greater accuracy than the one built without using it.

Benefiting from the digital beam control method, the model-to-part accuracy of the system is effectively improved. The digital scanning system is feasible in rapid manufacturing large and complex three-dimensional metal parts.

The surface roughness of products manufactured using the additive manufacturing (AM) technology of electron beam melting (EBM) has a special characteristic. Different product applications can demand rougher or finer surface structure, so the purpose of this study is to investigate the process parameters of EBM to find out how they affect surface roughness.

EBM uses metal powder to manufacture metal parts. A design of experiment plan was used to describe the effects of the process parameters on the average surface roughness of vertical surfaces.

The most important electron beam setting for surface roughness, according to this study, is a combination of “speed and current” in the contours. The second most important parameter is “contour offset”. The interaction between the “number of contours” and “contour offset” also appears to be important, as it shows a much higher probability of being active than any other interaction. The results show that the “line offset” is not important when using contours.

This study examined “contour offset”, “number of contours”, “speed in combination with current” and “line offset”, which are process parameters controlling the electron beam.

The surface properties could have an impact on the product’s performance. A reduction in surface processing will not only save time and money but also reduce the environmental impact.

Surface properties are important for many products. New themes containing process parameters have to be developed when introducing new materials to EBM manufacturing. During this process, it is very important to understand how the electron beam affects the melt pool.

THE conversion of the kinetic energy of a beam of electrons into heat on striking a metal work‐piece has been known for a very long time, a patent was in fact taken out for an electron beam melting device by Pirani in 1905. It was not, however, until the late 1950s that serious attempts were made to use more refined devices for welding. The main difference between the early melting machines and present day welding devices lies in the degree of power intensity due to beam focusing developments which lead to the discovery of a completely new welding mechanism.