TiC/Ti Composite Layers Fabricated by Laser Surface Alloying

2007 ◽  
Vol 336-338 ◽  
pp. 1148-1150
Author(s):  
Jian Bin Zhang ◽  
Ding Fan ◽  
Jing Jie Dai ◽  
Yao Ning Sun
Keyword(s):  
Continuous Wave ◽  
Composite Layer ◽  
Pure Titanium ◽  
Surface Hardness ◽  
Laser Surface ◽  
Commercially Pure Titanium ◽  
Surface Alloying ◽  
Micro Hardness ◽  
Laser Surface Alloying ◽  
Commercially Pure

Laser surface alloying is an attractive processing to improve surface hardness, wear and corrosion resistance. In this paper, a continuous wave CO2 laser was used to irradiate commercially pure titanium surface with pre-placed active carbon powders in argon atmosphere. A compact, well-adherent, and crack-free TiC/Ti composite layer was obtained. The microstructure and phase constitution of the alloyed layers were determined and analyzed, and the micro-hardness was measured. The result of X ray diffraction (XRD) analysis shows that the alloyed layers contain TiC and Ti (martensite). The scanning electron microscopy (SEM) observation shows TiC growth morphologies have a well-developed dendrite, cellular dendrite, globular microstructure and cross-petal microstructure. The mechanism of the formation of titanium carbides is discussed. Micro-hardness of the laser surface alloyed layer was improved to 420 Hv as compared to 200 Hv of the as-received commercially pure titanium.

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.

Microstructures of Laser Processed Fe-Cr Surface Alloys

1981 ◽  
Vol 39 ◽  
pp. 328-329
Author(s):  
P. A. Molian ◽  
K. H. Khan ◽  
W. E. Wood
Keyword(s):  
Cooling Rate ◽  
Pure Iron ◽  
Continuous Wave ◽  
Laser Surface ◽  
Material Surface ◽  
Constitution Diagram ◽  
Incident Power ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

Wear Assessment of Ti/SiC Surface Nano-Composite Layer and its Associated CP-Ti Substrate

2012 ◽  
Vol 445 ◽  
pp. 595-600 ◽  
Author(s):  
Ali Shamsipur ◽  
Seyed Farshid Kashani-Bozorg ◽  
Abbas Zarei Hanzaki
Keyword(s):  
Surface Layer ◽  
Wear Behavior ◽  
Composite Layer ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Micro Hardness ◽  
Wear Properties ◽  
Friction Stir ◽  
Pin On Disc ◽  
Cp Ti

In the present investigation, the surface of a commercially pure titanium (CP-Ti) substrate was modified to Ti/SiC nanocomposite layer employing friction stir processing technique; nanosized SiC powder was introduced into the stir zone provided by a rotating and advancing tool. The fabricated nanocomposite surface layer exhibited a micro hardness value of ~535HV which is much greater than 160HV of the substrate material using Vickers micro hardness testing. In addition, the un-treated CP-Ti substrate showed sever wear regime in the pin-on-disc test against the hardened AISI 52100 steel. It suffers extensive typical adhesive wear dominated by plastic deformation as evidenced by scanning electron microscopy. Also, deep grooves were formed, i.e. evidence of abrasive wear. Contrary to this, enhanced wear properties were detected for the Ti/SiC nanocomposite surface layer, i.e. lower coefficient of friction and weight loss. The nanocomposite surface layer was found to be adherent to the underlying substrate during the pin-on-disc test. The superior wear behavior of the nanocomposite surface layer is attributed to its improved micro hardness value due to the presence of hard nanosize SiC particles in a refined titanium matrix.

Experimental Study of Laser Surface Treatment of Low-Carbon Ductile Iron

2012 ◽  
Vol 155-156 ◽  
pp. 965-968
Author(s):  
Yu Zhong Li ◽  
Jing Ping Liu
Keyword(s):  
Surface Treatment ◽  
Ductile Iron ◽  
Surface Hardness ◽  
Laser Surface ◽  
Low Carbon ◽  
Surface Alloying ◽  
Laser Surface Treatment ◽  
Iron Matrix ◽  
Laser Surface Alloying ◽  
Surface Laser

In the essay, the Low carbon ductile iron by laser surface alloying processing has been experimentally studied. Results indicate that on low carbon ductile iron matrix coated with different alloy powder, structure of laser surface alloying processing is very small, the combination quality between alloying layer and matrix is good. Low carbon ductile iron after laser surface treatment, maternal surface hardness are greatly enhanced, maternal surface hardness increasing from HV250~330 to the highest about HV1400, surface laser hardening effect of Low carbon ductile iron is very obvious.

Comparison of Commercially Pure Titanium Surface Hardness Improvement by Plasma Nitrocarburizing and Ion Implantation

2013 ◽  
Vol 789 ◽  
pp. 347-351 ◽  
Author(s):  
Agung Setyo Darmawan ◽  
Waluyo Adi Siswanto ◽  
Tjipto Sujitno
Keyword(s):  
Ion Implantation ◽  
Elevated Temperatures ◽  
Pure Titanium ◽  
Surface Hardness ◽  
Commercially Pure Titanium ◽  
Hardness Tester ◽  
Hardness Number ◽  
Commercially Pure ◽  
Hardness Tests ◽  
Plasma Nitrocarburizing

Commercially pure (cp) titanium has a relative soft hardness property. In particular usage such as sliding, the improvement of the surface hardness will be required. In this study, surface hardness improvement of cp titanium by Plasma Nitrocarburizing and Ion Implantation are compared. Plasma Nitrocarburizing processes are conducted at different elevated temperatures with different duration processes, i.e. at 350 °C for 3, 4, and 5 hours, and at 450 °C for 2, 3, and 4 hours respectively, while Ion Implantation processes are conducted at room temperature and process durations are varied as 2.3 hours, 4.7 hours, and 9.3 hours. Nitrogen ions are used to implant the material. Hardness tests are then performed on each specimen by using Micro Vickers Hardness Tester. The surface hardness number (HV) for specimens of the Plasma Nitrocarburizing processes at temperature of 350 °C for process duration of 3 hours, 4 hours, and 5 hours are 74.16, 92.25 and 94.41, respectively while those at temperature of 450 °C for duration process of 2 hours, 3 hours, and 4 hours are 103.70, 121.31 and 126.17, respectively. The processes of Ion Implantation produce the surface hardness number (HV) of 88.97, 125.51, and 130.2, for duration processes of 2.3 hours, 4.7 hours, and 9.3 hours. The process of Ion Implantation produce higher surface hardness number than the Plasma Nitrocarburizing process at temperature 350 °C but the surface hardness number is lower when compared to the Plasma Nitrocarburizing at a temperature of 450 °C. For the duration processes 4 hours and more, the process of Ion Implantation produces the same surface hardness number with the Plasma Nitrocarburizing at temperature of 450 °C.

Laser surface alloying of pure titanium with TiN–B–Si–Ni mixed powders

2005 ◽  
Vol 250 (1-4) ◽  
pp. 223-227 ◽  
Author(s):  
Y.S. Tian ◽  
C.Z. Chen ◽  
D.Y. Wang ◽  
Q.H. Huo ◽  
T.Q. Lei
Keyword(s):  
Pure Titanium ◽  
Laser Surface ◽  
Surface Alloying ◽  
Laser Surface Alloying
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