scholarly journals Laser-Sustained Plasma (LSP) Nitriding of Titanium: A Review

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 283 ◽  
Author(s):  
Amar M. Kamat ◽  
Stephen M. Copley ◽  
Albert E. Segall ◽  
Judith A. Todd
Keyword(s):  
Wear Resistance ◽  
Gas Flow ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Surface Hardness ◽  
Weight Ratio ◽  
High Strength ◽  
Nitrogen Plasma ◽  
Commercially Pure Titanium ◽  
Laser Nitriding

Titanium and its alloys possess several attractive properties that include a high strength-to-weight ratio, biocompatibility, and good corrosion resistance. However, due to their poor wear resistance, titanium components need to undergo surface hardening treatments before being used in applications involving high contact stresses. Laser nitriding is a thermochemical method of enhancing the surface hardness and wear resistance of titanium. This technique entails scanning the titanium substrate under a laser beam near its focal plane in the presence of nitrogen gas flow. At processing conditions characterized by low scan speeds, high laser powers, and small off-focal distances, a nitrogen plasma can be struck near the surface of the titanium substrate. When the substrate is removed, this plasma can be sustained indefinitely and away from any potentially interacting surfaces, by the laser power and a cascade ionization process. This paper presents a critical review of the literature pertaining to the laser nitriding of titanium in the presence of a laser-sustained plasma, with the ultimate objective of forming wide-area, deep, crack-free, wear-resistant nitrided cases on commercially pure titanium substrates.

In vitro Behaviour of Alumina-Hydroxiapatite Composites Coatings

2018 ◽  
Vol 69 (6) ◽  
pp. 1416-1418
Author(s):  
Alexandru Szabo ◽  
Ilare Bordeasu ◽  
Ion Dragos Utu ◽  
Ion Mitelea
Keyword(s):  
Pure Titanium ◽  
Titanium Substrate ◽  
High Strength ◽  
Biological Properties ◽  
Commercially Pure Titanium ◽  
Hvof Spraying ◽  
Before And After ◽  
Sbf Solution ◽  
Oxygen Fuel

Hydroxyapatite (HA) is a very common material used for biomedical applications. Usually, in order to improve its poor mechanical properties is combined or coated with other high-strength materials.The present paper reports the manufacturing and the biocompatibility behaviour of two different biocomposite coatings consisting of alumina (Al2O3) and hydroxyapatite (HA) using the high velocity oxygen fuel (HVOF) spraying method which were deposited onto the surface of a commercially pure titanium substrate. The biological properties of the Al2O3-HA materials were evaluated by in vitro studies. The morphology of the coatings before and after their immersing in the simulated body fluid (SBF) solution was characterized by scanning electron microscopy (SEM). The results showed an important germination of the biologic hydroxyapatite crystallite on the surface of both coatings.

Structure and Phase Composition of a Ti Film–Al Substrate System Irradiated with an Intense Pulsed Electron Beam

2018 ◽  
Vol 781 ◽  
pp. 101-107
Author(s):  
Yurii Ivanov ◽  
Olga V. Krysina ◽  
Pavel Moskvin ◽  
Elizaveta A. Petrikova ◽  
Olga V. Ivanova ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Electron Beam ◽  
High Surface ◽  
Pure Titanium ◽  
Surface Hardness ◽  
Vacuum Arc ◽  
High Wear Resistance ◽  
Commercially Pure Titanium ◽  
Plasma Cathode ◽  
Commercially Pure

Commercially pure A7 aluminum was exposed to surface modification in a single vacuum cycle which included vacuum arc evaporation and deposition of commercially pure titanium and intense electron beam irradiation and melting of the film–substrate system using a plasma-cathode pulsed electron source. The deposited Ti film thickness was 0.5 and 1 μm. The irradiated Ti–Al system revealed a multilayer multiphase structure consisting of submicro-and nanosized elements with intermetallic inclusions Al3Ti, Al2Ti, and TiAl3. The Ti film during irradiation broke up into fragments with their immersion in the molten Al surface layer to a depth of 20 μm. The modified material surpassed the initial aluminum in wear resistance by a factor of 2.4 and in microhardness by a factor larger than 4. The main cause for the high surface hardness and high wear resistance of the modified aluminum was likely the formation of both the intermetallic particles and the Ti-hardened transition layer.

Simulation and Experimental Study of Nanosecond Laser Micromachining of Commercially Pure Titanium

2015 ◽  
Vol 4 (1) ◽  
Author(s):  
E. Williams ◽  
E. B. Brousseau
Keyword(s):  
Laser System ◽  
Pulse Length ◽  
Pure Titanium ◽  
Weight Ratio ◽  
High Strength ◽  
Single Pulse ◽  
Small Scale ◽  
Nanosecond Laser ◽  
Commercially Pure Titanium ◽  
Commercially Pure

Nanosecond laser machining of titanium has gained increased interest in recent years for a number of potential applications where part functionalities depend on features or surface structures with microscale dimensions. In particular, titanium is one of the materials of choice to sustain the demand for advanced and miniaturized components in the biomedical and aerospace sectors for instance. This is due to its inherent properties of high strength-to-weight ratio, corrosion resistance, and biocompatibility. However, in the nanosecond laser processing regime, the resolidification and deposition of material expelled from the generated craters can be detrimental to the achieved machined quality at such small scale. Thus, this paper focuses on the investigation of the laser–material interaction process in this pulse length regime as a function of both the delivered laser beam energy and the pulse duration in order to optimize machining quality and throughput. To achieve this, a simple theoretical model for simulating single pulse processing was developed and validated first. The model was then used to relate (1) the temperature evolution inside commercially pure titanium targets with (2) the morphology of the obtained craters. Using a single fiber laser system with a wavelength of 1064 nm, this analysis was conducted for pulse durations comprised between 25 ns and 220 ns and a range of fluence values from 14 J cm−2 and 56 J cm−2. One of the main conclusions from the study is that the generation of relatively clean single craters could be best achieved with a pulse length in the range of 85–140 ns when the delivered fluence leads to the maximum crater temperature being above but still relatively close to the vaporization threshold of the cpTi substrate. In addition, the lowest surface roughness in the case of laser milling operations could be obtained when the delivered single pulses did not lead to the vaporization threshold being reached.

Laser Engineered Net Shaping of Commercially Pure Titanium: Effects of Fabricating Variables

2016 ◽  
Author(s):  
Yingbin Hu ◽  
Hui Wang ◽  
Fuda Ning ◽  
Weilong Cong
Keyword(s):  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Pure Titanium ◽  
Weight Ratio ◽  
High Strength ◽  
Commercially Pure Titanium ◽  
Laser Engineered Net Shaping ◽  
Commercially Pure ◽  
Net Shaping ◽  
Cp Ti

Commercially pure titanium (CP-Ti) attracts a large number of attentions in biomedical, astronautical, and auto industrial areas due to its superior properties of good biocompatibility, excellent corrosion resistance, and high strength-to-weight ratio. Comparing with the conventional manufacturing processes (such as casting along with machining), laser additive manufacturing (LAM), mainly including selective laser sintering/melting (SLS/M) and laser engineered net shaping (LENS), has many advantages, such as complex shaped parts producing, more capability of shorter design-to-market time, energy consumption reducing, etc. It was reported that SLS/M has been successfully used in fabricating of CP-Ti components. Comparing with SLS/M processes, LENS has many advantages, including lower labor intensity, higher fabrication efficiency, and more capabilities for parts repairing and rebuilding. It is reported that LENS process was only used in CP-Ti coating and porous parts fabrication, there are no reported investigations on CP-Ti three-dimensional (3D) solid parts using LENS process. The investigations in this paper are going to conduct preliminary studies on effect of fabricating variables. In order to evaluate powder efficiency and parts’ quality, heights of fabricated parts and hardness on the top surface of the parts will be tested.

Influence of Duplex Treatment on Structural and Tribological Properties of Commercially Pure Titanium

2017 ◽  
Vol 36 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Ilhan Çelik
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Physical Vapor Deposition ◽  
Plasma Nitriding ◽  
Pure Titanium ◽  
Surface Hardness ◽  
Compound Layer ◽  
Commercially Pure Titanium ◽  
Wear Properties ◽  
Commercially Pure

AbstractTitanium and its alloys are widely used in many fields, including aerospace and the chemical and biomedical industries. This is due to their mechanical properties, excellent corrosion resistance, and biocompatibility although they do have poor wear resistance. In this study, a duplex layer was successfully formed on the commercially pure titanium surface by duplex treatments (plasma nitriding and physical vapor deposition (PVD)). In the initial treatment, plasma nitriding was performed on the pure titanium samples and in the second treatment, the nitrided samples were coated with CrN by PVD. The friction and wear properties of the duplex-treated samples were investigated for tribological applications. Surface morphology and microstructure of the duplex-treated samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, the tribological properties were investigated using pin-on-disc tribometer. A compound layer composed of ε-Ti2N and δ-TiN phases and a diffusion layer formed under the compound layer were obtained on the surface of pure titanium after the nitriding treatments. CrN coated on the nitrided surface provided an increase in the surface hardness and in the wear resistance.

Wear Behavior of Pure Titanium Coated With WC-Co by the Use of Electrospark Deposition Method

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Seyyed Jaber Razavi Arab ◽  
Hossein Aghajani
Keyword(s):  
Wear Resistance ◽  
Wear Behavior ◽  
Pure Titanium ◽  
Weight Ratio ◽  
High Strength ◽  
Deposition Process ◽  
Deposition Method ◽  
Electrospark Deposition ◽  
Substrate Properties ◽  
Pin On Disk

Titanium is a highly interesting material in engineering because of its unique combination of high strength to weight ratio, excellent resistance to corrosion, and biocompatibility. However, the material’s low wear resistance, which is its inherent nature, limits its application in highly erosive conditions. In order to enhance the wear resistance of biomedical grade titanium with the help of a WC-Co coating, an electrospark deposition method was used in this work. The goal of this work is to investigate the effect of frequency and current upper limit in the electrospark deposition process on substrate properties. Hardness of the layers was measured by a microhardness tester. In order to study the morphology and microstructure of surface layers, scanning electron microscope was used. Tribological tests were conducted under technically dry friction conditions at a load of 12.5 N by a pin-on-disk tribometer. Titanium was observed in coating and metallurgical bonding between the coating and the substrate. The optimized sample's hardness was about 930 HV 0.1. Results showed that the presence of a carbide layer on the surface of titanium leads to a great enhancement of wear resistance of about 68% in the pin-on-disk test.

Solidification in Laser Cladding of a Ti-Si Graded Coating on Pure Titanium Substrate

2013 ◽  
Vol 739 ◽  
pp. 196-200 ◽  
Author(s):  
T.M. Yue ◽  
K.J. Huang ◽  
H. Xie
Keyword(s):  
Laser Cladding ◽  
Solid Solutions ◽  
Silicon Content ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Eutectic Growth ◽  
Commercially Pure Titanium ◽  
Commercially Pure ◽  
Graded Coating

A three-layer Ti-Si graded coating was fabricated on a commercially pure titanium substrate by laser cladding with Ti-5.8 at%Si, Ti-9.0 at%Si and Ti-13.5 at%Si mixed powders. The microstructure of the three layers comprised Ti-Si solid solutions (Ti) and the Ti5Si3 compound. As the silicon content was increased, the microstructure along the direction of deposition underwent a series of changes, including replacement of the (Ti) phase by the primary Ti5Si3 phase, and a change of the (Ti)/Ti5Si3 eutectic growth from lamellar to anomalous.

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