Influence of hot isostatic pressing and surface finish on the mechanical behaviour of Ti6Al4V processed by electron beam melting

2020 ◽  
Vol 43 (12) ◽  
pp. 2828-2841
Author(s):  
Stefania Franchitti ◽  
Carmine Pirozzi ◽  
Rosario Borrelli
Keyword(s):  
Electron Beam ◽  
Surface Finish ◽  
Mechanical Behaviour ◽  
Electron Beam Melting ◽  
Hot Isostatic Pressing ◽  
Isostatic Pressing

scholarly journals Encapsulation of Electron Beam Melting Produced Alloy 718 to Reduce Surface Connected Defects by Hot Isostatic Pressing

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1226 ◽  
Author(s):  
Yunus Emre Zafer ◽  
Sneha Goel ◽  
Ashish Ganvir ◽  
Anton Jansson ◽  
Shrikant Joshi
Keyword(s):  
Electron Beam ◽  
Electron Beam Melting ◽  
Surface Defects ◽  
High Surface ◽  
Hot Isostatic Pressing ◽  
Coated Sample ◽  
Alloy 718 ◽  
Isostatic Pressing ◽  
Before And After ◽  
X Ray Computed

Defects in electron beam melting (EBM) manufactured Alloy 718 are inevitable to some extent, and are of concern as they can degrade mechanical properties of the material. Therefore, EBM-manufactured Alloy 718 is typically subjected to post-treatment to improve the properties of the as-built material. Although hot isostatic pressing (HIPing) is usually employed to close the defects, it is widely known that HIPing cannot close open-to-surface defects. Therefore, in this work, a hypothesis is formulated that if the surface of the EBM-manufactured specimen is suitably coated to encapsulate the EBM-manufactured specimen, then HIPing can be effective in healing such surface-connected defects. The EBM-manufactured Alloy 718 specimens were coated by high-velocity air fuel (HVAF) spraying using Alloy 718 powder prior to HIPing to evaluate the above approach. X-ray computed tomography (XCT) analysis of the defects in the same coated sample before and after HIPing showed that some of the defects connected to the EBM specimen surface were effectively encapsulated by the coating, as they were closed after HIPing. However, some of these surface-connected defects were retained. The reason for such remnant defects is attributed to the presence of interconnected pathways between the ambient and the original as-built surface of the EBM specimen, as the specimens were not coated on all sides. These pathways were also exaggerated by the high surface roughness of the EBM material and could have provided an additional path for argon infiltration, apart from the uncoated sides, thereby hindering complete densification of the specimen during HIPing.

scholarly journals Effect of Hot Isostatic Pressing on Microstructures and Mechanical Properties of Ti6Al4V Fabricated by Electron Beam Melting

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 593
Author(s):  
Changyong Liu ◽  
Zhuokeng Mai ◽  
Deng Yan ◽  
Mingguang Jiang ◽  
Yuhong Dai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Grain Size ◽  
Electron Beam ◽  
Electron Beam Melting ◽  
Hot Isostatic Pressing ◽  
Phase Ratio ◽  
Lamellar Thickness ◽  
Isostatic Pressing ◽  
Β Phase

This study investigated the effects of hot isostatic pressing (HIP) on the microstructures and mechanical properties of Ti6Al4V fabricated by electron beam melting (EBM). The differences of surface morphologies, internal defects, relative density, microstructures, textures, mechanical properties and tensile fracture between the as-built and HIPed samples were observed using various characterization methods including optical metallography microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD) and tensile tests. It was found that the main effects of HIP on microstructures include—the increase of average grain size from 7.96 ± 1.21 μm to 11.34 ± 1.89 μm, the increase of α lamellar thickness from 0.71 ± 0.15 μm to 2.49 ± 1.29 μm and the increase of β phase ratio from 4.7% to 10.5% in terms of area fraction on the transversal section. The combinatorial effects including densification, increase of grain size, α lamellar thickness, β phase ratio, reduction of dislocation density and transformation of dislocation patterns contributed to the improvement of elongation and ductility of EBM-fabricated Ti6Al4V. Meanwhile, these effects also resulted in a slight reduction of the yield strength and UTS mainly due to the coarsening effect of HIP.

Effect of HIPping (Hot Isostatic Pressing) on electron beam melting Ti6Al4V parts after machining

2016 ◽  
Author(s):  
Adrien Dolimont ◽  
Sebastien Michotte ◽  
Edouard Rivière-Lorphèvre ◽  
François Ducobu ◽  
Charlotte de Formanoir ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Beam Melting ◽  
Hot Isostatic Pressing ◽  
Isostatic Pressing

scholarly journals ВПЛИВ ТЕХНОЛОГІЙ ПІДВЕДЕННЯ ЕНЕРГІЇ ПРИ 3D-ПРИНТИНГУ НА СТРУКТУРУ ТА ВЛАСТИВОСТІ ДЕТАЛЕЙ ЗІ СПЛАВУ Ti-6Al-4V

2018 ◽  
pp. 86-90
Author(s):  
Алексей Александрович Педаш ◽  
Владимир Валериевич Клочихин ◽  
Тамара Александровна Митина ◽  
Валерий Григорьевич Шило
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Selective Laser Melting ◽  
Electron Beam Melting ◽  
Melt Inclusions ◽  
Hot Isostatic Pressing ◽  
Alpha Phase ◽  
Laser Melting ◽  
Isostatic Pressing ◽  
The Impact

The composition, structure and mechanical properties of samples obtained from the titanium alloy Ti-6Al-4V, by selective laser melting and electron beam melting processes regarding production of responsible aviation parts were carrying-out at present article.A comparative study of macro- and microstructure, mechanical properties has been carried out after inherent of Ti-6Al-4V heat treatment with or without prior hot isostatic pressing.It was established that the advent in specimens fractures and microstructure pores and non-melt inclusions of a granules condition obligatory hot isostatic pressing of a responsible parts when this kinds of defects significantly releases and correspondingly best complex of mechanical properties are obtained.The powders from titanium Ti-6Al-4V alloy were produce by inert gas (argon) spraying process and had a different particle sizing distribution: 20-50 microns for selective laser melting and 45-105 microns for electron beam melting.The microstructure of the specimens prepared using the studied production processes features an elongated lamellar alpha phase in the transformated epitaxially grown beta-matrix and is typical for Ti-6Al-4V alloy in a heat-treated condition.It has been noted that the lamellar alpha phase in the structure of the studied specimens after hot isostatic pressing is distinguished by larger sizes in width as compared to the specimens prior to hot isostatic pressing processing.Mechanical properties of the specimens produced by selective laser melting or electron beam melting processes meet the specification requirements. Hot isostatic pressing processing results in a remarkable improvement of the impact strength.  Authors should be pointed out that application of additive technologies in the manufacture of aerospace parts requires extensive research&development works, and testing efforts to confirm repeatability of alloy characteristics. A mandatory procedure of the production process and material approval shall be conducted to ensure compliance with aircraft flight safety standards and regulations.

Impact of hot isostatic pressing on microstructures of CMSX-4 Ni-base superalloy fabricated by selective electron beam melting

2016 ◽  
Vol 110 ◽  
pp. 720-727 ◽  
Author(s):  
B. Ruttert ◽  
M. Ramsperger ◽  
L. Mujica Roncery ◽  
I. Lopez-Galilea ◽  
C. Körner ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Beam Melting ◽  
Hot Isostatic Pressing ◽  
Isostatic Pressing ◽  
Selective Electron Beam Melting ◽  
Base Superalloy
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