CREATION OF A HETEROGENEOUS MATERIAL BASED ON THE TITANIUM ALLOY AND TITANIUM BORIDE BY SELECTIVE LASER MELTING

2021 ◽  
Vol 62 (5) ◽  
pp. 752-759
Author(s):  
V. M. Fomin ◽  
T. A. Brusentseva ◽  
A. A. Golyshev ◽  
A. G. Malilkov ◽  
A. V. Mishin ◽  
...  
Author(s):  
Weipeng Duan ◽  
Meiping Wu ◽  
Jitai Han

TC4, which is one of the most widely used titanium alloy, is frequently used in biomedical field due to its biocompatible. In this work, selective laser melting (SLM) was used to manufacture TC4 parts and the printed parts were heat-treated using laser rescanning technology. The experimental results showed that laser rescanning had a high impact on the quality of SLMed part, and a different performance on wear resistance can be found on the basis. It can be seen that the volume porosity of the sample was 7.6 ± 0.5% without using any further processing technology. The volume porosity of the sample processed using laser rescanning strategy was decreased and the square-framed rescanning strategy had a relative optimal volume porosity (1.5 ± 0.3%) in all these five samples. With the further decreasing of volume porosity, the wear resistance decreased at the same time. As its excellent bio-tribological properties, the square-framed rescanning may be a potential suitable strategy to forming TC4 which used in human body.


Author(s):  
Haiyang Fan ◽  
Yahui Liu ◽  
Shoufeng Yang

Ti–6Al–2Sn–4Zr–2Mo (Ti-6242), a near-[Formula: see text] titanium alloy explicitly designed for high-temperature applications, consists of a martensitic structure after selective laser melting (SLM). However, martensite is thermally unstable and thus adverse to the long-term service at high temperatures. Hence, understanding martensite decomposition is a high priority for seeking post-heat treatment for SLMed Ti-6242. Besides, compared to the room-temperature titanium alloys like Ti–6Al–4V, aging treatment is indispensable to high-temperature near-[Formula: see text] titanium alloys so that their microstructures and mechanical properties are pre-stabilized before working at elevated temperatures. Therefore, the aging response of the material is another concern of this study. To elaborate the two concerns, SLMed Ti-6242 was first isothermally annealed at 650[Formula: see text]C and then water-quenched to room temperature, followed by standard aging at 595[Formula: see text]C. The microstructure analysis revealed a temperature-dependent martensite decomposition, which proceeded sluggishly at [Formula: see text]C despite a long duration but rapidly transformed into lamellar [Formula: see text] above the martensite transition zone (770[Formula: see text]C). As heating to [Formula: see text]C), it produced a coarse microstructure containing new martensites formed in water quenching. The subsequent mechanical testing indicated that SLM-built Ti-6242 is excellent in terms of both room- and high-temperature tensile properties, with around 1400 MPa (UTS)[Formula: see text]5% elongation and 1150 MPa (UTS)[Formula: see text]10% elongation, respectively. However, the combination of water quenching and aging embrittled the as-built material severely.


2017 ◽  
Vol 44 (9) ◽  
pp. 0902001
Author(s):  
肖振楠 Xiao Zhennan ◽  
刘婷婷 Liu Tingting ◽  
廖文和 Liao Wenhe ◽  
张长东 Zhang Changdong ◽  
杨涛 Yang Tao

Author(s):  
Ashwin Polishetty ◽  
Guy Littlefair

Titanium is known for its poor machinability characteristics due to its low thermal conductivity and high chemical reactivity. This article explores the machinability characteristics of selective laser melting (SLM) titanium alloy Ti-6Al-4V using wire cut electrical discharge machining (WEDM). For titanium alloys, exploring non-traditional machining operation such as WEDM is critical for a material failure or success in a design application. The research is to study the effect of parameters such as servo voltage, pulse on/off, and machining speed with respect to wire tension and wire feed rate on machinability. The outputs under consideration for evaluating machinability are metal removal rate (MRR) and surface finish under minimal interruption due to wire snaps. The article concludes by identifying the optimal factors responsible to produce an efficient and accurate cut with a minimum downtime.


2018 ◽  
Vol 91 (4) ◽  
pp. 452-457 ◽  
Author(s):  
Avram Manea ◽  
Simion Bran ◽  
Mihaela Baciut ◽  
Gabriel Armencea ◽  
Dumitru Pop ◽  
...  

Background and aims. Although dental implants are widely and successfully used, failure rates because of bacterial colonization are still high. Adequate fabrication and sterilization techniques as well as proper management of infectious complications represent a constant field of interest and research. In this study, we focused our attention on implants with controlled porosity produced by Selective Laser Melting (SLM). The difficulty to sterilize porous implantable devices is well known and finding an adequate sterilization protocol represents a challenge worldwide. Before testing the biological and mechanical properties of porous implants, a preliminary study in order to determine a correct sterilization protocol must be conducted.Our aim was to establish a valid sterilization protocol for porous titanium alloy dental implants, as such protocols are not officially available yet.Methods. Twenty dental implants were fabricated from a titanium alloy by SLM. Ten of them were made using a 150W laser beam (porosity of 1% - group A) and the rest using a 75W laser beam (porosity of 23% - Group B), all of them with a non-defined internal structure. The implants were initially sterilized (5 from group A and 5 from group B, using dry heat - 180°C for 2 hours; the rest using steam sterilization - 121 °C for15 min) and then spent 18 hours in culture media with developing bacteria (Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 49444), Enterococcus faecalis (ATCC 29212), Listeria monocytogenes (ATCC 19114), three Gram negative bacteria: Escherichia coli (ATCC 25922), Salmonella typhimurium (ATCC 14028) and Pseudomonas aeruginosa (ATCC 27853). The first ten implants (5 from group A and 5 from group B) were then sterilized with dry heat and the others with steam. After sterilization, they were all placed in sterile culture media in order to observe if any bacterial growth were present.Results. The culture media was observed 18 hours after the sterilized implants were placed inside. No bacterial growth was observed.Conclusions. Our tests reached their aims of defining a protocol to sterilize porous implants. Future tests regarding biological and mechanical aspects of these implants may now follow.


2017 ◽  
Vol 8 (3) ◽  
pp. 475-479 ◽  
Author(s):  
C. Zopp ◽  
S. Blümer ◽  
F. Schubert ◽  
L. Kroll

Sign in / Sign up

Export Citation Format

Share Document