Performance Evaluation of Superhard Coatings in Drilling of Ti-6Al-4V Alloy

2017 ◽  
Author(s):  
Dinh Nguyen ◽  
Patrick Kwon ◽  
Vadim Voznyuk ◽  
Dave Kim
Keyword(s):  
Flank Wear ◽  
Weight Ratio ◽  
High Strength ◽  
Production Costs ◽  
Confocal Laser ◽  
Adhesion Layer ◽  
Ti Alloys ◽  
Aerospace Manufacturing ◽  
Catastrophic Fracture ◽  
Superhard Coatings

In the aerospace industry, titanium (Ti) alloys, especially Ti6Al4V, has been extensively used over other light weight alloys due to their high strength-to-weight ratio. However, the material and production costs have been major obstacles in the adoption of Ti alloys for a wide variety of applications. The machining of Ti alloys is one of the most time consuming and expensive mechanical processes in aerospace manufacturing. Based on previous literature on the topic, coated drills have had some degree of success in the drilling of Ti. To further the work, this paper conducts a comparative study in which Ti6Al4V plates are drilled with super hard coated drills such as Diamond-like-Carbon (DLC), AlMgB14 (BAM) and nanocomposite AlCrSiN. The results are compared with those of an uncoated drill bit. Working with a coating supplier, several variations of BAM coating have been applied and used in our drilling experiments. To evaluate the performance of these drills, scanning electron microscopy and confocal laser microscopy were used to assess the wear progress of each drill qualitatively and quantitatively. In drilling Ti alloys, the primary mechanisms of flank wear are abrasion, microscopic fracture (chipping) and attrition, which result in the detachment of the adhesion layer located at the cutting edge. For all the drills, the predominant wear occurs near the margin. From our drilling experiments, it has been observed that AlCrSiN and BAM drills have survived up to 58 holes and over 80 holes, respectively, while both uncoated and DLC drills have experienced catastrophic fracture at less than 40 holes.

An assessment into mechanical properties and microstructural behavior of TIG welded Ti-6Al-4V titanium alloy

2020 ◽  
Vol 10 (3) ◽  
pp. 281-292 ◽  
Author(s):  
Saurabh Dewangan ◽  
Suraj Kumar Mohapatra ◽  
Abhishek Sharma
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weight Ratio ◽  
High Strength ◽  
Hardness Test ◽  
Content Type ◽  
Ti Alloys ◽  
Microstructure And Mechanical Properties ◽  
Grade 5 ◽  
Selection Of

PurposeTitanium (Ti) alloys are in high demand in manufacturing industries all over the world. The property like high strength to weight ratio makes Ti alloys highly recommended for aerospace industries. Ti alloys possess good weldability, and therefore, they were extensively investigated with regard to strength and metallurgical properties of welded joint. This study aims to deal with the analysis of strength and microstructural changes in Ti-6Al-4V (Grade 5) alloy after tungsten inert gas (TIG) welding.Design/methodology/approachTwo pair of Ti alloy plates were welded in two different voltages, i.e. 24 and 28 V, with keeping the current constant, i.e. 80 A It was a random selection of current and voltage values to check the performance of welded material. Both the welded plates were undergone through some mechanical property analysis like impact test, tensile test and hardness test. In addition, the microstructure of the welded joints was also analyzed.FindingsIt was found that hardness and tensile properties gets improved with an increment in voltage, but this effect was reverse for impact toughness. A good corroboration between microstructure and mechanical properties, such as tensile strength, hardness and toughness, was reported in this work. Heat distribution in both the welded plates was simulated through ANSYS software to check the temperature contour in the plates.Originality/valueA good corroboration between microstructure and mechanical properties, such as tensile strength, hardness and toughness, was reported in this study.

Fatigue in Ti-6Al-4V at Very High Cycles

2007 ◽  
Vol 561-565 ◽  
pp. 259-262 ◽  
Author(s):  
X.J. Cao ◽  
M.R. Sriraman ◽  
Qing Yuan Wang
Keyword(s):  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Weight Ratio ◽  
High Strength ◽  
Ambient Air ◽  
Ti Alloys ◽  
Structural Applications ◽  
Ultrasonic Fatigue ◽  
Reversed Loading ◽  
Very High

The importance of determining and understanding the very high cycle fatigue behaviors of materials has gained strength in recent years. Ti-alloys, in view of their high strength-to-weight ratio, have a range of structural applications. Of these, Ti-6Al-4V, belonging to the alpha-beta type is the most widely used. The present paper deals with investigations on the fatigue behavior of TC4, the Chinese equivalent to Ti-6Al-4V, up to very high cycles. Fatigue testing was carried out on a piezoelectric ultrasonic fatigue machine operating at 20 kHz frequency. Hourglass shaped resonant specimens were tested in ambient air at room temperature under completely reversed loading conditions (R = -1). Failure in the alloy was seen to occur right up to the gigacycle regime, with the fractures being found to initiate from the surface unlike in steels. The fracture surfaces exhibit brittle characteristics containing river patterns and cleavage facets, as well as striations.

Superplastic Forming/Diffusion Bonding of a Titanium Alloy for the Realization of an Aircraft Structural Component in Multi-Sheets Configuration

2012 ◽  
Vol 504-506 ◽  
pp. 717-722 ◽  
Author(s):  
Luigi Carrino ◽  
Valentino Paradiso ◽  
Stefania Franchitti ◽  
Antonino Squillace ◽  
Salvatore Russo
Keyword(s):  
Diffusion Bonding ◽  
Weight Ratio ◽  
Superplastic Forming ◽  
High Strength ◽  
Production Costs ◽  
Single Shot ◽  
Forming Process ◽  
Element Analysis ◽  
Thickness Prediction ◽  
Superplastic Properties

Superplastic forming and diffusion bonding (SPF/DB) is a near-net-shape forming and joining process used with alloys having superplastic properties in order to make manufact which should have light weight and high stiffness. The aerospace is one of those sectors in which such technology is mainly used. This process allows to reduce the buy-to-fly ratio and consequently the production costs thanks to the possibility to produce complex shape components in a single shot. The material widely used for this application is the Ti-6Al-4V alloy for its high strength vs weight ratio, excellent mechanical proprieties, corrosion resistance and galvanic compatibility with carbon fiber reinforced composite materials. In this study, finite element analysis of the SPF/DB process has been carried out in order to investigate the thickness prediction, the optimization of the tooling’s geometry and the definition of the sheets initial thickness in the blow forming process of a multi-sheets configuration.

Studies on Porous Titanium Alloy Implant Manufactured by Three Dimensional Solid Freeform Fabrication System

2007 ◽  
Vol 29-30 ◽  
pp. 107-110 ◽  
Author(s):  
K.K. Lim ◽  
P. Cheang ◽  
M. Chandrasekaran
Keyword(s):  
Solid Freeform Fabrication ◽  
Three Dimensional ◽  
Weight Ratio ◽  
High Strength ◽  
Porous Titanium ◽  
Water Soluble ◽  
Ti Alloy ◽  
Mechanically Alloyed ◽  
Freeform Fabrication ◽  
Ti Alloys

Titanium (Ti) alloys have emerged to become valuable biomaterials for biomedical and orthopedic applications due to their high strength to weight ratio, excellent biocompatibility and corrosion resistance. In this study, the authors utilized Solid Freeform Fabrication (SFF), also commonly known as a rapid prototyping technology to investigate a new porous three-dimensional (3D) Ti alloy implant. Elemental powders for producing a Ti-Al-Fe-Zr alloy were mechanically alloyed and blended with water soluble binder material. The blended powders were manufactured by Three Dimensional Printer (3DP), followed by debinding and sintering in an inert environment. The effects of process parameters on structural and geometrical requirements were assessed. Results from these investigations demonstrated that Ti alloys are promising biomaterials for near net shape fabrication of porous 3D implants, which retained their interconnected pore network. As an illustration, complex geometries of porous 3D Ti alloy specimens were manufactured as a demonstration of 3D SFF System.

In Vitro Cytotoxicity of Binary Ti Alloys for Bone Implants

2009 ◽  
Vol 618-619 ◽  
pp. 295-298 ◽  
Author(s):  
Yun Cang Li ◽  
Cynthia Wong ◽  
Jian Yu Xiong ◽  
Peter D. Hodgson ◽  
Cui E Wen
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
In Vitro Cytotoxicity ◽  
Osteosarcoma Cell ◽  
Human Osteosarcoma Cell Line ◽  
Human Osteosarcoma ◽  
Ti Alloys ◽  
Human Osteosarcoma Cell ◽  
Cell Shapes

Interest in using titanium (Ti) alloys as load-bearing implant materials has increased due to their high strength to weight ratio, lower elastic modulus, and superior biocompatibility and enhanced corrosion resistance compared to conventional metals such as stainless steel and Co-Cr alloys. In the present study, the in vitro cytotoxicity of five binary titanium alloys, Ti15Ta, Ti15Nb, Ti15Zr, Ti15Sn and Ti15Mo, was assessed using human osteosarcoma cell line, SaOS-2 cells. The Cell proliferation and viability were determined, and cell adhesion and morphology on the surfaces of the binary Ti alloys after cell culture were observed by SEM. Results indicated that the Ti binary alloys of Ti15Ta, Ti15Nb and Ti15Zr exhibited the same level of excellent biocompatibility; Ti15Sn alloy exhibited a moderate biocompatibility while Ti15Mo alloy exhibited a moderate cytotoxicity. The SaOS-2 osteoblast-like cells had flattened and spread across the surfaces of the Ti15Ta, Ti15Nb, Ti15Zr and Ti15Sn groups; however, the cell shapes on the Ti15Mo alloy was shrinking and unhealthy. These results indicated that the Mo contents should be limited to a certain level in the design and development of new Ti alloys for implant material applications.

scholarly journals FIB-SEM Investigation of Laser-Induced Periodic Surface Structures and Conical Surface Microstructures on D16T (AA2024-T4) Alloy

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 144 ◽  
Author(s):  
Igor A. Salimon ◽  
Sakellaris Mailis ◽  
Alexey I. Salimon ◽  
Evgenij Skupnevskiy ◽  
Svetlana A. Lipovskikh ◽  
...  
Keyword(s):  
Laser Treatment ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Structures ◽  
Confocal Laser ◽  
Formation Mechanisms ◽  
Sem Images ◽  
Periodic Surface

The use of aluminum alloy AA2024-T4 (Russian designation D16T) in applications requiring a high strength-to-weight ratio and fatigue resistance such as aircraft fuselage often demands the control and modification of surface properties. A promising route to surface conditioning of Al alloys is laser treatment. In the present work, the formation of ripples and conical microstructures under scanning with femtosecond (fs) laser pulses was investigated. Laser treatment was performed using 250 fs pulses of a 1033 nm Yb:YAG laser. The fluence of the pulses varied from 5 to 33 J/cm2. The scanning was repeated from 1 to 5 times for different areas of the sample. Treated areas were evaluated using focused ion beam (FIB)- scanning electron microscopy (SEM) imaging and sectioning, energy-dispersive X-ray (EDX) spectroscopy, atomic force microscopy (AFM), and confocal laser profilometry. The period of laser-induced periodic surface structures (LIPSS) and the average spacing of conical microstructures were deduced from SEM images by FFT. Unevenness of the treated areas was observed that is likely to have been caused by ablation debris. The structural and elemental changes of the material inside the conical microstructures was revealed by FIB-SEM and EDX. The underlying formation mechanisms of observed structures are discussed in this paper.

The Origin of Flank Wear in Turning Ti-6Al-4V

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Trung Nguyen ◽  
Patrick Kwon ◽  
Di Kang ◽  
Thomas R. Bieler
Keyword(s):  
Cutting Tool ◽  
Flank Wear ◽  
Polycrystalline Diamond ◽  
Confocal Microscope ◽  
Hard Phase ◽  
Adhesion Layer ◽  
Electron Backscattered Diffraction ◽  
Tool Materials ◽  
Orientation Image Microscopy ◽  
Ti Alloys

Unlike ferrous materials, where the cementite (Fe3C) phase acts as an abrasive that contributes to flank wear on the cutting tool, most titanium (Ti) alloys possesses no significant hard phase. Thus, the origin of flank wear is unclear in machining Ti alloys. To address this question, a Ti-6Al-4V bar was turned under various conditions with uncoated carbide and polycrystalline diamond (PCD) inserts, most commonly used tool materials for machining Ti alloys. These inserts were retrieved sporadically while tuning to examine the wear patterns using a confocal microscope. To correlate the patterns with the microstructure of the original bar, the microstructure was carefully characterized using Orientation Image Microscopy™ (OIM) with electron-backscattered diffraction (EBSD). From the wear patterns, two distinct types of damage were identified: (a) microscopic and macroscopic fractures on the cutting edges and (b) scoring marks on flank faces. This paper demonstrates that both types of damage were caused primarily by the heterogeneity in hardness in the α-crystals, where the plane perpendicular to the c-axis in an α-crystal is substantially harder than any other direction in the α-crystal as well as the isotropic β-crystal. In addition to such heterogeneities, adhesion layer, ubiquitous to machining Ti alloys, detaches small fragments of the tool, which resulted in microscopic and macroscopic fractures observed on flank wear.

The Root Cause of Nose and Flank Wear and Their Behavior in Turning Ti-6Al-4V With Carbides and PCD Inserts

2014 ◽  
Author(s):  
Trung Nguyen ◽  
Patrick Kwon ◽  
D. Kang ◽  
Tom Bieler
Keyword(s):  
Flank Wear ◽  
Cutting Tools ◽  
Tool Material ◽  
Hard Phase ◽  
Adhesion Layer ◽  
Electron Backscattered Diffraction ◽  
Root Cause ◽  
Ti Alloys ◽  
Ferrous Metals ◽  
Hexagonal Closed Packed

This paper addresses the root cause for flank and nose wear when machining Ti alloys. In machining ferrous metals, at least the cementite (Fe3C) phase is present as the abrasive contributing to the flank wear. However, most titanium alloys possesses no significant hard phase, which questions the root cause for those wear. In this study, a Ti-6Al-4V bar was turned under various conditions with few grades of uncoated carbide and PCD-insert type tools. The cutting tools were retrieved sporadically after stopping the tuning process in order to examine the wear patterns and their evolution on the tools. The nose and flank wear patterns on the tool inserts were investigated with a confocal microscope. The microstructure of the bar was characterized using Orientation Image Microscope with Electron-Backscattered Diffraction Scan (EBDS). Two distinct types of damages were identified, (a) Micro-fracture at the cutting edge and (b) Scoring markings. Based on the microstructure and the tool wear patterns, this paper claims that both types of damages were caused primarily by the hard orientation of the alpha (α or Hexagonal Closed Packed) crystalline phases and secondarily by the adhesion layer detaching parts of the tool material from the nose and flank surfaces.

Precipitation in Al-Li-Zr alloys

1992 ◽  
Vol 50 (1) ◽  
pp. 186-187
Author(s):  
D.M. Vanderwalker
Keyword(s):  
Fracture Toughness ◽  
Precipitation Hardening ◽  
Weight Ratio ◽  
High Strength ◽  
Transmission Electron ◽  
Water Quench ◽  
Aluminum Lithium ◽  
Aluminum Lithium Alloys ◽  
Lithium Alloys ◽  
Zr Alloys

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.

TUNGUM ALLOY

Alloy Digest ◽  
2012 ◽  
Vol 61 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Weight Ratio ◽  
High Strength ◽  
Fatigue Properties ◽  
Excellent Corrosion Resistance

Abstract Tungum alloy combines an unusually high strength-to-weight ratio, with ductility, excellent corrosion resistance, and good fatigue properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Cu-806. Producer or source: Tungum Ltd.

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