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.

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.

Thermomechanical Response of Commercially Pure Titanium under Large Plastic Deformation at High Strain Rates

2012 ◽  
Vol 548 ◽  
pp. 174-178 ◽  
Author(s):  
Chong Yang Gao ◽  
Wei Ran Lu
Keyword(s):  
Pure Titanium ◽  
Optimal Solution ◽  
Optimization Method ◽  
Strain Rates ◽  
Commercially Pure Titanium ◽  
Thermomechanical Response ◽  
Commercially Pure ◽  
Different Temperatures ◽  
Cp Ti ◽  
Constitutive Parameters

By using a dislocation-based plastic constitutive model for hcp metals developed by us recently, the dynamic thermomechanical response of an important industrial material, commercially pure titanium (CP-Ti), was described at different temperatures and strain rates. The constitutive parameters of the material are determined by an efficient optimization method for a globally optimal solution. The model can well predict the dynamic response of CP-Ti by the comparison with experimental data and the Nemat-Nasser-Guo model.

The Influence of Laser Irradiation Parameters on Tribological Behaviour of Commercially Pure Titanium for Dental Prostheses

2016 ◽  
Author(s):  
Karibeeran Shanmuga Sundaram ◽  
Gurusami Kiliyappan ◽  
Senthil Kumaran Selvadurai
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Pure Titanium ◽  
Laser Surface ◽  
Commercially Pure Titanium ◽  
Laser Shock ◽  
Micro Hardness ◽  
Dental Prostheses ◽  
Commercially Pure ◽  
Cp Ti

Laser shock peening (LSP) is one of the innovative technique that produces a compressive residual stress on the surface of metallic materials, thereby significantly increasing its fatigue life in applications where failure is caused by surface-initiated cracks. The specimens were treated with laser shock waves with different processing parameters, and characterization studies were made on treated specimens. The purpose of the present study was to investigate the influence of Nd:YAG laser on commercially pure titanium (CP-Ti) used in prosthetic dental restorations. The treatment influenced change in microstructure, micro hardness, surface roughness, and wear resistance characteristics. Though CP-Ti is considered as an excellent material for dental applications due to its outstanding biocompatibility, it is not suitable when high mastication forces are applied. In the present study, pulsed Nd:YAG laser surface treatment technique was adopted to improve the wear resistance of CP-Ti. The wear test pin specimens of CP-Ti were investment cast with centrifugal titanium casting machine. The wear properties of specimens were evaluated after LSP on a “pin-on-disc” wear testing tribometer, as per ASTM G99-05 standards. The results of the wear experiment showed that the treated laser surface has higher wear resistance, micro hardness, and surface roughness compared to as-cast samples. The improvement of wear resistance may be attributed due to grain refinement imparted by LSP processes. The microstructure, wear surfaces, wear debris, and morphology of the specimen were analyzed by using optical electron microscope, scanning electron microscope, and X-ray diffraction (XRD). The data were compared using ANOVA and post-hoc Tukey tests. The characteristic change resulted in increase in wear resistance and decrease in wear rate. Hence, it is evident that the more reliable and removable partial denture metal frameworks for dental prostheses may find its applications.

scholarly journals The influence of mold temperature on the fit of cast crowns with commercially pure titanium

2005 ◽  
Vol 19 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Wagner Sotero Fragoso ◽  
Guilherme Elias Pessanha Henriques ◽  
Edwin Fernando Ruiz Contreras ◽  
Marcelo Ferraz Mesquita
Keyword(s):  
Pure Titanium ◽  
Mold Temperature ◽  
Commercially Pure Titanium ◽  
Mechanical Grinding ◽  
Marginal Fit ◽  
Commercially Pure ◽  
Cp Ti

Commercially pure titanium (CP Ti) has been widely applied to fabricate cast devices because of its favorable properties. However, the mold temperature recommended for the manufacture of casts has been considered relatively low, causing inadequate castability and poor marginal fit of cast crowns. This study evaluated and compared the influence of mold temperature (430°C - as control, 550°C, 670°C) on the marginal discrepancies of cast CP Ti crowns. Eight bovine teeth were prepared on a mechanical grinding device and impressions were used to duplicate each tooth and produce eight master dies. Twenty-four crowns were fabricated using CP Ti in three different groups of mold temperature (n = 8): 430°C (as control), 550°C and 670°C. The gap between the crown and the bovine tooth was measured at 50 X magnification with a traveling microscope. The marginal fit values of the cast CP Ti crowns were submitted to the Kruskal-Wallis test (p = 0.03). The 550°C group (95.0 µm) showed significantly better marginal fit than the crowns of the 430°C group (203.4 µm) and 670°C group (213.8 µm). Better marginal fit for cast CP Ti crowns was observed with the mold temperature of 550°C, differing from the 430°C recommended by the manufacturer.

Pack Cementation Treatment of Titanium Using Tetracalcium Phosphate Powder for Biomedical Applications

2010 ◽  
Vol 654-656 ◽  
pp. 2172-2175
Author(s):  
Kyosuke Ueda ◽  
Hajime Suto ◽  
Kaori Nakaie ◽  
Takayuki Narushima
Keyword(s):  
Reaction Layer ◽  
Biomedical Applications ◽  
Pure Titanium ◽  
Pack Cementation ◽  
Apatite Formation ◽  
Commercially Pure Titanium ◽  
Tetracalcium Phosphate ◽  
Phosphate Powder ◽  
Commercially Pure ◽  
Cp Ti

The surface modification of commercially pure titanium (CP Ti) by pack cementation treatment at 973 K using tetracalcium phosphate (Ca4(PO4)2O, TTCP) slurry was investigated. An HAp phase and a CaTiO3 phase were observed on the reaction layer of the CP Ti substrate after pack cementation treatment at 973 K for 86.4 ks. TTCP powder decomposed to HAp and CaO, and CaO reacted with TiO2 to form CaTiO3. The reaction layer on the CP Ti substrate consisted of inner and outer layers and the particles were in the outer reaction layer. The pores observed on the reaction layer were formed by the detachment of particles from the outer layer. The bonding strength of the reaction layer was 68.1 MPa. Apatite completely covered the surface of the pack-cementation-treated CP Ti after immersion in Kokubo solution for 21.6 ks; such rapid apatite formation suggests that pack cementation treatment improves the biocompatibility of titanium.

scholarly journals Characterisation and modelling of in-plane springback in a commercially pure titanium (CP-Ti)

2018 ◽  
Vol 53 (9) ◽  
pp. 6872-6892 ◽  
Author(s):  
S. Khayatzadeh ◽  
M. J. Thomas ◽  
Y. Millet ◽  
S. Rahimi
Keyword(s):  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Commercially Pure ◽  
Cp Ti

Surface characterization of nanostructured commercially pure titanium modified by sandblasting and acid-etching for implant applications

2019 ◽  
Vol 234 (3) ◽  
pp. 414-423 ◽  
Author(s):  
F Reshadi ◽  
S Khorasani ◽  
G Faraji
Keyword(s):  
Contact Angle ◽  
Pure Titanium ◽  
Surface Characteristics ◽  
Ultrafine Grain ◽  
Acid Etching ◽  
Commercially Pure Titanium ◽  
Commercially Pure ◽  
Mg63 Cells ◽  
Average Grain Size ◽  
Cp Ti

This study investigated the surface characteristics of ultrafine-grain commercially pure titanium (UFG CP-Ti) substrates produced by equal channel angular pressing (ECAP), compared with those of coarse-grain commercially pure titanium (CG CP-Ti) and Ti–6Al–4V (Ti-64) substrates. All Ti surfaces were sandblasted and acid-etched (SLA-treated) to produce micro-rough surfaces. Tensile and microhardness tests were carried out to measure the mechanical properties of fabricated samples. Then the surface characteristics of samples including contact angle measurements, surface morphology and in vitro cell response were evaluated after polishing, sandblasting and acid etching procedures. The results showed that after applying four passes of ECAP, the average grain size of microstructure decreased from 25 µm to 170 nm, while the ultimate tensile strength increased from 545 ± 24 MPa to 971 ± 38 MPa. Investigation of surface morphologies carried out by scanning electron microscopy indicated that ECAP-processed substrate exhibits nano-topography compared with CG CP-Ti and Ti-64 substrates after applying SLA process. In addition, the contact angle of SLA-treated CG CP-Ti and UFG CP-Ti substrates decreased from 68.3° to 9.5° and 51.9° to 7.4°, respectively, indicating a significant improvement of surface wettability. The morphologies of MG63 cells cultured on the developed surfaces proved the potential superior osteoblast cell compatibility of the micro-roughened surface made of UFG CP-Ti substrates over CG CP-Ti and Ti-64 substrates.

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