scholarly journals Feasibility Study of Compaction and Sintering of Commercially Pure Titanium using Friction Stir Processing

2018 ◽  
Vol 8 (3) ◽  
Author(s):  
Aleksandra Fortier ◽  
Nilesh Kumar ◽  
Mageshwari Komarasamy ◽  
Rajiv S. Mishra
Keyword(s):  
Friction Stir Processing ◽  
Manufacturing Process ◽  
Capital Investment ◽  
Pure Titanium ◽  
Peak Hardness ◽  
Commercially Pure Titanium ◽  
Friction Stir ◽  
Commercially Pure ◽  
Average Grain Size ◽  
Ti Powder

Manufacturing of a component through powder metallurgy (PM) route involves at least three critical steps: powder blending, compaction, and sintering. Overall, the PM route takes 4 to 8 steps to get to the final product. Moreover, it requires a huge amount of capital investment to perform every step of the manufacturing process via PM route. Friction stir processing (FSP) is a derivative of friction stir welding which has emerged as a generic microstructural modification tool in last one decade. The aim of the current work was to explore the possibility of decreasing the number of steps required in the manufacturing of a product using the PM technique. Using the FSP method, the manufacturing process is reduced to two steps and the mechanical properties of the final product are significantly improved. In this study, commercially pure titanium (Ti) powder was used. The two-step process appeared extremely efficient and it involved: 1) constraining the Ti-powder in a die and using a punch to consolidate it in a final disk-like geometry, 2) next, the consolidated disk-shaped product was processed using FSP tool and methods. Initial mechanical characterization results show peak hardness of the FSP processed Ti-powder product to be approximately 436 HV0.3 with average hardness measured at about 251 HV. The electron backscattered diffraction of the FSP-assisted sintered region showed equiaxed grains with average grain size to be 440 ±254 nm. The initial result indicates FSP can be used as a manufacturing tool for consolidating powders in to bulk solid form.

scholarly journals Wear of ZhS6U Nickel Superalloy Tool in Friction Stir Processing on Commercially Pure Titanium

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 799 ◽  
Author(s):  
Alihan Amirov ◽  
Alexander Eliseev ◽  
Evgeny Kolubaev ◽  
Andrey Filippov ◽  
Valery Rubtsov
Keyword(s):  
Friction Stir Welding ◽  
Tool Wear ◽  
Friction Stir Processing ◽  
Chemical Elements ◽  
Pure Titanium ◽  
Nickel Superalloy ◽  
Commercially Pure Titanium ◽  
Friction Stir ◽  
Commercially Pure ◽  
Residual Stresses And Strains

The use of electric arc or gas welding in the manufacture of titanium components often results in low quality welded joints due to large residual stresses and strains. A successful solution to this problem can be found in the application of friction stir welding. However, friction stir welding (FSW) of titanium alloys is complicated by rapid tool wear under high loads and temperatures achieved in the process. This paper studies the durability of a tool made of ZhS6U Ni-based superalloy used for friction stir processing of commercially pure titanium and the effect of the tool wear on the weld quality. The total length of the titanium weld formed by the tool without failure comprised 2755 mm. The highest wear of the tool is observed at the base of the pin, which brings about the formation of macrodefects in the processed material. The tool overheating causes an increase in the dendrite element size of ZhS6U alloy. The transfer layer contains chemical elements of this alloy, indicating that the tool wear occurs by diffusion and adhesion. As a result of processing, the tensile strength of commercially pure titanium increased by 25%.

FABRICATION OF TI/SIC SURFACE NANO-COMPOSITE LAYER BY FRICTION STIR PROCESSING

2012 ◽  
Vol 05 ◽  
pp. 367-374 ◽  
Author(s):  
ALI SHAMSIPUR ◽  
SEYED FARSHID KASHANI-BOZORG ◽  
ABBAS ZAREIE-HANZAKI
Keyword(s):  
Friction Stir Processing ◽  
Composite Layer ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Commercially Pure Titanium ◽  
Nano Composite ◽  
Composite Surface ◽  
Friction Stir ◽  
Commercially Pure ◽  
Sic Particles

In the present investigation, novel Ti / SiC surface nano-composite layer was successfully fabricated by dispersing nano-sized SiC particles into commercially pure titanium plates employing friction stir processing technique. The process parameters such as tool rotation and advancing speeds were adjusted to produce defect-free surface composite layer, however, uniform distribution of the nano-size SiC particles in a matrix of titanium was achieved after the second pass. The micro hardness value of the Ti / SiC nano-composite surface layer was found to be ~534 HV; this is 3.3 times higher than that of the commercially pure titanium substrate. No reaction was detected between SiC powders and the titanium matrix after friction stir processing.

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.

scholarly journals Influence of Inhomogeneity on Mechanical Properties of Commercially Pure Titanium Processed by HPT

2018 ◽  
Vol 385 ◽  
pp. 284-289 ◽  
Author(s):  
Alexander P. Zhilyaev ◽  
Yi Huang ◽  
Jose María Cabrera ◽  
Terence G. Langdon
Keyword(s):  
Mechanical Properties ◽  
High Pressure Torsion ◽  
Structural Phase ◽  
Pure Titanium ◽  
High Strength ◽  
Alpha Phase ◽  
Commercially Pure Titanium ◽  
Omega Phase ◽  
Commercially Pure ◽  
Ti Powder

Already for fifteen years many researchers have been trying to discover metallic materials with unusual combinations of strength and ductility: with high strength and enhanced ductility. This combination may be achieved through different ways: alloying, nanostructuring, etc. This report is an attempt to analyze the influence of inhomogeneity of different types (structural, phase and space) on mechanical properties of commercially pure titanium (bulk and powder) subjected to high-pressure torsion. Experimental results for HPT bulk and powder titanium have demonstrated that mechanical behavior of CP titanium strongly depends on phase inhomogeneity (alpha + omega phases), structural inhomogeneity (bimodal grain size distribution) and space inhomogeneity (retained porosity) in case of cold consolidated Ti powder. High strength in HPT bulk titanium due to the formation of hard omega phase during HPT processing at room temperature was detected. The strong omega phase transforms back to nanograined alpha phase domains during short annealing at elevated temperature. HPT consolidation of titanium powder leads to the formation of brittle specimens showing high strength but almost zero plasticity.

Effects of Grain Size and Texture on the Biocompatibility of Commercially Pure Titanium

2011 ◽  
Vol 702-703 ◽  
pp. 822-825 ◽  
Author(s):  
Majid Hoseini ◽  
Philippe Bocher ◽  
Fereshteh Azari ◽  
Hojatollah Vali ◽  
Jerzy A. Szpunar
Keyword(s):  
Grain Size ◽  
Cell Attachment ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
X Ray Diffraction ◽  
Fine Grained ◽  
Angular Pressing ◽  
Commercially Pure ◽  
Average Grain Size ◽  
Electron Back Scattered Diffraction

Ultra fine grained (UFG) pure titanium fabricated by severe plastic deformation techniques has been recently considered for biomedical applications. In this study, the effects of grain size and crystallographic orientation on the biocompatibility of commercially pure titanium have been evaluated. Samples having significant differences in terms of average grain size (from 0.4 to 20 mm) and crystallographic textures have been produced using equal channel angular pressing (ECAP) and compared. X-ray diffraction and electron back scattered diffraction (EBSD) were used to document the texture and microstructural properties. Cell attachment tests were done to study the biocompatibility of the samples using MC3T3 pre-osteoblast cells. The number of attached cells was found to be higher on the samples having more (0002) plane parallel to the surface regardless of their grain sizes. It was concluded that the texture plays a more significant role than the grain size in the biocompatibility of pure titanium.

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