Surface Hardening of Titanium Articles With Titanium Boride Layers and its Effects on Substrate Shape and Surface Texture

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Anthony P. Sanders ◽  
Nishant Tikekar ◽  
Curtis Lee ◽  
K. S. Ravi Chandran
Keyword(s):  
Surface Texture ◽  
Raw Materials ◽  
Titanium Boride ◽  
Boride Coating ◽  
Shape Distortion ◽  
Surface Textures ◽  
Biomedical Implant ◽  
Fine Microstructure ◽  
Diffusion Boriding ◽  
Boriding Process

There is widespread interest in engineering improved properties into the surface layer of manufactured articles. One method for doing so involves a novel boriding process that creates hardened surface layers by the growth of a dual layer TiB2+TiB coating on titanium articles. The objective of the present work was to demonstrate the fundamental feasibility of this process by producing uniform thick boride coating layers on titanium articles and to polish them to a very fine surface texture suitable for biomedical implant bearing surfaces. A powder pack diffusion boriding process was used to grow dual layer TiB2+TiB coatings on simple shapes. Lapping processes were used to polish the borided articles. Evaluation was carried out using measurements of surface texture, geometric form, and hardness, and by metallurgical analysis. Boriding on as-received titanium articles resulted in shape distortion that hampered the subsequent polishing efforts. Hence, further articles were treated with stress-relief annealing prior to boriding, at temperatures below and above the β-transus of the substrate article. Annealing itself caused some form distortion, which was eliminated by lapping. Then, after boriding the annealed articles, varying surface textures and shape distortions were observed. Articles annealed above the β-transus had surface textures with significant peak-to-valley roughness (14–55 μm), and the texture appeared to be patterned upon the substrate microstructure. However, form distortion seemed to be alleviated. For articles annealed below the β-transus, form distortion was not alleviated, and the articles exhibited wavy surface textures with a high peak-to-valley roughness (up to 50 μm). Whether combined or independent, the surface texture changes and shape distortion that occurred during boriding thwarted the polishing processes; the articles could not be uniformly polished to a roughness less than 0.05 μm within the coating thickness. To achieve uniformly polished dual layer TiB2+TiB surfaces on titanium articles using the pack boriding technique, it appears that the substrate raw materials should be free of residual stresses and consist of a fine microstructure.

scholarly journals Comparison of the Influences of Surface Texture and Boundary Slip on Tribological Performances

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Qiyin Lin ◽  
Baotong Li
Keyword(s):  
Surface Texture ◽  
Slip Velocity ◽  
Structure Parameters ◽  
Textured Surfaces ◽  
Slider Bearing ◽  
Boundary Slip ◽  
Surface Textures ◽  
Slip Surfaces ◽  
Texture Structure ◽  
The Relationship

Close attentions have been widely paid to the engineering textured and slip surfaces for improving bearing tribological performances. Comparison studies on the tribological characteristics of slip and textured surfaces are carried out in this work. The analysis results point out that the influences of surface texture and boundary slip on tribological performances of slider bearing are strongly similar. For the determinate surface textures, there is one and only value of slip velocity to make the tribological performances of textured and slip surfaces in agreement. The corresponding relation between the slip velocity and the texture structure parameters is also obtained, and the size of slip velocity is directly related to the texture geometry parameters including its position parameters. This study will help us to further understand the relationship between boundary slip and surface texture and also the slip phenomenon.

Formation of boride layers on a commercially pure Ti surface produced via powder metallurgy

2021 ◽  
Vol 112 (4) ◽  
pp. 303-307
Author(s):  
Yavuz Kaplan ◽  
Mehmet Gülsün ◽  
Sinan Aksöz
Keyword(s):  
Powder Metallurgy ◽  
Substrate Surface ◽  
High Hardness ◽  
Titanium Boride ◽  
Boride Layer ◽  
Powder Metallurgy Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Commercially Pure ◽  
Boriding Process

Abstract In this study, powder metallurgy was applied in a furnace atmosphere to form titanium boride layers on a commercially pure Ti surface. Experiments were carried out using the solid-state boriding method at 900 °C and 1000°C for 12 h and 24 h. Samples were produced by pressing the commercially pure Ti powders under 870 MPa. The sintering process required by the powder metallurgy method was carried out simultaneously with the boriding process. Thus, the sintering and boriding were performed in one stage. The formation of the boride layer was investigated by field emission scanning electron microscopy, optical-light microscopy, X-ray diffraction, and elemental dispersion spectrometry analyses. In addition, microhardness measurements were performed to examine the effect of the boriding process on hardness. The Vickers microhardness of the boronized surface reached 1773 HV, which was much higher than the 150 HV hardness of the commercially pure Ti substrate. The X-ray diffraction analysis showed that the boriding process had enabled the formation of TiB and TiB2 on the powder metallurgy Ti substrate surface. Consequently, the production of Ti via powder metallurgy is a potentially cost-effective alternative to the conventional method, and the boriding process supplies TiB and TiB2 that provide super-high hardness and excellent wear and corrosion resistance.

scholarly journals The Development of Surface Roughness and Implications for Cellular Attachment in Biomedical Applications

2001 ◽  
Vol 705 ◽  
Author(s):  
Bruce Banks ◽  
Sharon Miller ◽  
Kim de Groh ◽  
Amy Chan ◽  
Mandeep Sahota
Keyword(s):  
Surface Roughness ◽  
Computational Modeling ◽  
Surface Texture ◽  
Atomic Oxygen ◽  
Treatment Time ◽  
Ion Beam ◽  
Cleveland Clinic ◽  
Surface Textures ◽  
Grit Blasting ◽  
Cellular Attachment

AbstractThe application of a microscopic surface texture produced by ion beam sputter texturing to the surfaces of polymer implants has been shown to result in significant increases in cellular attachment compared to smooth surface implants in animal studies. A collaborative program between NASA Glenn Research Center and the Cleveland Clinic Foundation has been established to evaluate the potential for improving osteoblast attachment to surfaces that have been microscopically roughened by atomic oxygen texturing. The range of surface textures that is feasible depends upon both the texturing process and the duration of treatment. To determine whether surface texture saturates or continues to increase with treatment duration, an effort was conducted to examine the development of surface textures produced by various physical and chemical erosion processes. Both experimental tests and computational modeling were performed to explore the growth of surface texture with treatment time. Surface texturing by means of abrasive grit blasting of glass, stainless steel and polymethylmethacrylate surfaces was examined to measure the growth in roughness with grit blasting duration by surface profilometry measurements. Laboratory tests and computational modeling was also conducted to examine the development of texture on Aclar® (chlorotrifluoroethylene) and Kapton® polyimide, respectively. For the atomic oxygen texturing tests of Aclar®, atomic force microscopy was used to measure the development of texture with atomic oxygen fluence. The results of all the testing and computational modeling support the premise that development of surface roughness obeys Poisson statistics. The results indicate that surface roughness does not saturate but increases as the square root of the treatment time.

Strain Induced Inward Grain Growth during Recrystallisation in Steel Sheets with BCC Crystal Structure

2012 ◽  
Vol 715-716 ◽  
pp. 303-308
Author(s):  
Jai Gautam ◽  
Roumen H. Petrov ◽  
Elke Leunis ◽  
Leo Kestens
Keyword(s):  
Surface Texture ◽  
Boundary Migration ◽  
Annealing Treatment ◽  
Random Surface ◽  
Surface Textures ◽  
Steel Sheets ◽  
Α Phase ◽  
Migration Mechanism ◽  
Different Types ◽  
Goss Orientation

The present paper investigates the potential application of Strain Induced Boundary Migration mechanism on the two different types of surface textures developed after α-γ-α phase transformation annealing, one with preferred cube and Goss orientation at the surface and the other with random surface texture without preferred orientations. It has been demonstrated that these surface texture components grow in across the thickness of the sheet after an appropriate combinations of a critical amount of rolling reductions and an annealing treatment at the recrystallisation temperature.

THE EFFECT OF SURFACE TEXTURE OF STEEL DISC ON FRICTION AND FRETTING WEAR

Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 39-48 ◽  
Author(s):  
Agnieszka LENART ◽  
Paweł PAWLUS ◽  
Andrzej DZIERWA ◽  
Mirosław TUPAJ
Keyword(s):  
Relative Humidity ◽  
Surface Texture ◽  
Normal Load ◽  
Fretting Wear ◽  
Surface Textures ◽  
Steel Disc ◽  
42Crmo4 Steel ◽  
Number Of Cycles ◽  
Effect Of Surface

Fretting tests were performed using an Optimol SRV5 tribotester in a ball-on-flat scheme. Balls from 100Cr6 steel of 60 HRC hardness and diameters of 10 mm co-acted with discs from 42CrMo4 steel of 47 HRC hardness under dry gross fretting conditions. Tests were performed at 300C and 25–35% relative humidity, and the number of cycles was 18000. During each test, the normal load was kept constant. Six sets of experiments were conducted. Discs had different surface textures as the result of machining. It was found that the lowest coefficients of friction were obtained for anisotropic surfaces when ball movements were perpendicular to main disc texture directions.

scholarly journals Image Scale Estimation Using Surface Textures for Quantitative Visual Inspection

2021 ◽  
Vol 6 (1) ◽  
pp. 1-3
Author(s):  
Juan Park ◽  
Chul Min Yeum ◽  
Trevor Hrynyk
Keyword(s):  
Neural Network ◽  
Regression Model ◽  
Convolutional Neural Network ◽  
Surface Texture ◽  
Visual Inspection ◽  
Estimation Error ◽  
Estimation Technique ◽  
Surface Textures ◽  
Scale Estimation ◽  
Using Data

In this study, a learning-based scale estimation technique is proposed to enable quantitative evaluation of inspection regions. The underlying idea is that surface texture of structures (i.e. bridges or buildings) captured on images contains the scale information of the corresponding images, which is represented by pixel per physical dimension (e.g., mm, inch). This allows training a regression model that provides a relationship between surface textures on images and their corresponding scales. Deep convolutional neural network is used to extract scale-related features from the texture patches and estimate their scales. The trained model can be exploited to estimate scales for all images captured from structure surfaces that have similar textures. The capability of the proposed technique is fully demonstrated using data collected from surface textures of three different structures and achieves an overall average scale estimation error of less than 15%.

scholarly journals Standard Versus Real Versus Fake Braces: Design And Microstructure Comparison

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Siti Hajjar Nasir ◽  
Noraini Abu Bakar ◽  
Rosdiyana Samad
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Surface Texture ◽  
Tooth Movement ◽  
Central Incisor ◽  
Surface Textures ◽  
Tooth Structure ◽  
Conventional Brackets ◽  
Scanning Electron

Introduction: The growing demand for orthodontic braces among Malaysian community has led to the development of "fake" and "real" braces. "Fake" braces refer to braces that are worn as costume and are not bonded to teeth hence unable to produce movement of teeth. "Real" braces refer to braces that are bonded to tooth structure and are able to produce tooth movement. The braces are bonded by unqualified practitioners with no formal dental education and they provide braces treatment in unlicensed premises such as hotel rooms or patients' own homes. Materials and Methods: This study was conducted to investigate the design and microstructure of several types of "fake", "real" and standard braces. A total of 9 upper right central incisor brackets were scanned using high resolution scanning electron microscopy (SEM) with magnifications of 65x, 500x and 1000x. Brackets slot heights and depths were also measured to compare slot dimensions between "fake", "real" and standard braces. Results: The surface textures of "fake" and "real" braces were noticeably more granular and unpolished as compared to conventional brackets. Furthermore, all "fake" and some "real" braces upper right central incisor bracket designs were distinctly different from the standard braces. The slot dimensions of "fake" and "real" braces were also significantly larger that standard braces. Conclusion(s): In conclusion, the surface texture and morphology of "fake" and "real" braces were crude and different when compared to conventional brackets.

Response of Metals and Polymers During Sliding: Role of Surface Texture

2010 ◽  
Author(s):  
Pradeep L. Menezes ◽  
Kishore ◽  
Satish V. Kailas ◽  
Michael R. Lovell
Keyword(s):  
Surface Texture ◽  
Hardened Steel ◽  
Steel Plates ◽  
Layer Formation ◽  
Transfer Layer ◽  
Surface Textures ◽  
Microscope Images ◽  
The Coefficient Of Friction ◽  
Plate Apparatus

Surface texture influences friction during sliding. In the present investigation, experiments were conducted using an inclined pin-on-plate apparatus to study the tribological response of metals and polymers during sliding against various surface textures. In the experiments, metals (Pb and Sn) and polymers (PP and PVC) were used for the pin and hardened steel was used for the plate. Experiments were conducted under both dry and lubricated conditions in an ambient environment. Two surface parameters of the steel plates — roughness and texture — were varied in the experiments. Using scanning electron microscope images, the surfaces of both the plate and pin materials were examined to determine the transfer layer formation on the plate and the wear of the pins. Based on the experimental results, it was observed that the transfer layer formation and the coefficient of friction were controlled by the surface texture of the plates. Moreover, both polymers and metals exhibited similar frictional responses, but the metals had a significantly larger variation in friction with surface texture.

Prediction of Boride Thickness on Tool Steels AISI D2 and AISI H13 Using Boriding Kinetics

2014 ◽  
Vol 931-932 ◽  
pp. 296-300 ◽  
Author(s):  
Yossapong Boonplook ◽  
Patiphan Juijerm
Keyword(s):  
Optical Microscope ◽  
Activation Energies ◽  
Boride Coating ◽  
Image Analyzer ◽  
Tool Steels ◽  
Near Surface ◽  
Aisi D2 ◽  
Aisi H13 ◽  
Boriding Process ◽  
Hot Work Tool Steels

Cold and hot work tool steels AISI D2 and AISI H13, respectively, were borided using a packed boriding process. Boriding temperature range of 1123 1223 K was performed with different boriding time up to 6 hr, afterwards, near-surface properties of the borided tool steels AISI D2 and H13 were characterized. Boride layer thicknesses were measured using an optical microscope with an image analyzer program. An X-ray diffraction (XRD) was performed to identify the boride coating layer. Kinetics of boriding process was analyzed using diffusion and Arrhenius equations. Activation energies and empirical data of the boriding process can be finally determined. It was found that the thickness of the boride coating increases with increasing boriding temperature and time taking into account the diffusion and Arrhenius equations. Activation energies of 177.4 and 185.7 kJ/mol were determined for cold and hot work tool steels AISI D2 and AISI H13, respectively. Thus, empirical relationships of boride thickness as a function of boriding temperature and time will be presented. Finally, predicted boride thickness diagram of cold and hot work tool steels AISI D2 and AISI H13, respectively can be established.

Effect of Surface Texture Molded by a Stainless Steel Mesh on the Invisalign Material Friction Coefficient

2015 ◽  
Vol 1090 ◽  
pp. 55-60
Author(s):  
Yong Qing Cai ◽  
Xiao Xiang Yang ◽  
Bing Wei He
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Surface Texture ◽  
Artificial Saliva ◽  
Mold Surface ◽  
Stainless Steel Mesh ◽  
Surface Textures ◽  
The Coefficient Of Friction ◽  
Material Coefficient ◽  
Effect Of Surface

Objective: This study aimed to evaluate the effect of surface texture mold by stainless steel (SS) mesh on Invisalign material friction coefficient. Materials and methods: Ten kinds of SS mesh were used to mold surface texture on Invisalign material. Experiments were conducted using a zirconia ball that slid against Invisalign material plates with different surface textures. In the experiments, the coefficients of friction under normal loads of 100, 200, and 300 g under dry and artificial saliva conditions were recorded. Results: The coefficient of friction was relative to the pore size and wire diameter of SS mesh. Conclusions: The Invisalign material coefficient can be effectively managed by the surface texture mold by SS mesh.

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