Simulation of Deformation Behavior and Microstructure Evolution during Hot Forging of TC11 Titanium Alloy

2018 ◽  
Vol 385 ◽  
pp. 449-454 ◽  
Author(s):  
Artem Alimov ◽  
Dmitry Zabelyan ◽  
Igor Burlakov ◽  
Igor Korotkov ◽  
Yuri Gladkov
Keyword(s):  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Technology Development ◽  
Hot Forging ◽  
Industrial Case Study ◽  
Aerospace Applications ◽  
Heating And Cooling ◽  
Tc11 Titanium Alloy ◽  
Kinetics Of

Finite element method is the most powerful tool for development and optimization of the metal forming processes. Analysis of titanium alloy critical parts should include the prediction of microstructure since their mechanical and technological properties essentially depend on the type and parameters of the microstructure. The technological process of parts production for aerospace applications is multi-operational and consists of deformation, heating and cooling stages. Therefore, it is necessary to simulate the microstructure evolution to obtain high quality parts. In presented paper FE simulation coupled with microstructure evolution during hot forging of TC11 titanium alloy has been performed by QForm FEM code. Constitutive relationships, friction conditions and microstructure evolution model have been established using the experiments. The kinetics of phase transformations has been described by the Johnson-Mehl-Avrami-Kolmogorov (JMAK) phenomenological model. The approach is illustrated by industrial case study that proved its practical applicability and economic advantages for technology development of titanium alloy critical parts.

The superplasticity and microstructure evolution of TC11 titanium alloy

2011 ◽  
Vol 32 (7) ◽  
pp. 3893-3899 ◽  
Author(s):  
Qian Jiang Sun ◽  
G.C. Wang ◽  
M.Q. Li
Keyword(s):  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Tc11 Titanium Alloy

scholarly journals Microstructure evolution and mechanical property response of TC11 titanium alloy under electroshock treatment

2021 ◽  
Vol 198 ◽  
pp. 109322
Author(s):  
Chang Liu ◽  
Lechun Xie ◽  
Dongsheng Qian ◽  
Lin Hua ◽  
Liqiang Wang ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Tc11 Titanium Alloy

scholarly journals FAST-forge of Titanium Alloy Swarf: A Solid-State Closed-Loop Recycling Approach for Aerospace Machining Waste

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 296 ◽  
Author(s):  
Nicholas S. Weston ◽  
Martin Jackson
Keyword(s):  
Titanium Alloy ◽  
Solid State ◽  
Closed Loop ◽  
Hot Forging ◽  
Weight Ratio ◽  
High Strength ◽  
Downstream Processing ◽  
Processing Route ◽  
Aerospace Applications ◽  
Multi Stage

Titanium alloys have excellent properties, but components are very expensive due to the high levels of processing required, such as vacuum melting, multi-stage forging, and machining. As a result, forged titanium alloy components are largely exclusive to the aerospace industry, where a high strength-to-weight ratio, corrosion resistance, and excellent fatigue resistance are essential. However, a typical buy-to-fly ratio for such components is approximately 9:1, as much of the forged billet is machined to swarf. The quantity of waste titanium alloy swarf generated is increasing as aircraft orders, and the titanium components contained within them, are increasing. In this paper, waste swarf material has been recycled using the two-step solid-state FAST-forge process, which utilizes field assisted sintering technology (FAST) followed by hot forging. Cleaned Ti-6Al-4V swarf was fully consolidated using the FAST process at sub-transus and super-transus temperatures, followed by hot forging at sub-transus temperatures at different strain rates. It was demonstrated that swarf-derived Ti-6Al-4V FAST billets have equivalent hot forging flow behaviour and resultant microstructures when directly compared to equivalently processed conventional expensive hydride–dehydride powder, and previously reported Kroll-derived melt-wrought material. This demonstrates that titanium swarf is a good quality feedstock for downstream processing. Additionally, FAST-forge is a viable processing route for the closed-loop recycling of machining waste for next-generation components in vehicles and non-aerospace applications, which is game changing for the economics of titanium alloy components.

scholarly journals Effect of Deformation Heating on Microstructure Evolution During Hot Forging of Ti-6Al-4V

2021 ◽  
Author(s):  
Mykola Kulakov ◽  
Salaheddin Rahimi ◽  
S. Lee Semiatin
Keyword(s):  
Microstructure Evolution ◽  
Volume Fraction ◽  
True Strain ◽  
Hot Forging ◽  
Solute Concentration ◽  
High Rate ◽  
Circular Cylinders ◽  
Deformation Heating ◽  
Heating And Cooling ◽  
High Rate Deformation

AbstractThe effect of deformation heating on microstructure evolution during hot forging of Ti-6Al-4V was established. For this purpose, right-circular cylinders of Ti-6Al-4V with an equiaxed-α preform microstructure were preheated to a temperature between 1148 K (875 °C) and 1223 K (950 °C), and compressed to a 60-pct. height reduction in a screw press, yielding average true strain rates of ~ 5 to 20 s−1. Thermocouple measurements and corroborating finite-element-method (FEM) simulations quantified substantial deformation-heating-induced temperature increases. For all preheat temperatures, the heating transient led to an exposure above the equilibriumβ transus temperature. Despite such temperature excursions, the volume fraction of equiaxed primary α in each forged billet was only slightly lower than that in the corresponding preheated condition. The source of such observations was rationalized on the basis of the (hypothesized) solute-concentration fields that develop during the heating and cooling transients experienced in high-rate deformation processing.

Die and Process Design for Hot Forging of a Gear Wheel – A Case Study

2013 ◽  
Vol 554-557 ◽  
pp. 307-316
Author(s):  
Thomas Henke ◽  
Markus Bambach ◽  
Gerhard Hirt
Keyword(s):  
Grain Growth ◽  
Microstructure Evolution ◽  
Process Design ◽  
Hot Forging ◽  
Laboratory Scale ◽  
Process Efficiency ◽  
Case Hardening ◽  
Grain Sizes ◽  
Mechanical Fatigue

Gearing components are an example for widely used machining parts in engines. Nowadays the development and optimization of materials and process chains are driven towards a concurrent improvement of final product properties and production efficiency. Excellent mechanical properties needed for gearing components e.g. high load capacity and high fatigue resistance depend on a fine homogeneous microstructure in the final product. Efficiency in gear manufacturing can be optimized by increasing the temperature during processing, which allows for lower forging loads and lower die stresses, thus improving die life in terms of mechanical fatigue. Additionally, increasing the temperature during case hardening reduces the process duration significantly. Hence process efficiency also increases. To meet the need of a fine homogenous microstructure, dynamic recrystallization has to be initiated during hot forging and grain growth has to be avoided during dwell times and case hardening. This grain size control can be achieved by applying micro-alloying concepts. Recently, an Nb-Ti-based alloying concept for case hardening steels was introduced, which increases fine grain stability and therefore potentially allows for higher forging and case hardening temperatures, leading to improved process efficiency [1]. In this paper a 25MoCr4-Nb-Ti steel grade is characterized in terms of flow resistance and microstructure evolution by hot compression tests and annealing experiments. The processing limits of this material in terms of abnormal grain growth are determined and a JMAK-based microstructure model considering these limits is presented and implemented in the FE-Software DEFORM 3dTM. The model is used in a case study to design a laboratory scale forging process for lowest possible die stresses and finest possible grain sizes. Experimentally measured grain sizes and forging loads from forgings at the laboratory scale are used to evaluate the process design. It is shown that considering microstructure evolution in process design is absolutely necessary to jointly optimize for process efficiency and final properties. The application of the Nb-Ti-based micro-alloying concepts allows for lower die stresses and thus seems to reduce mechanical fatigue of the dies compared to conventional case-hardening steels. [1] S. Konovalov et. al.: Testcase gearing component. In: G. J. Schmitz, U. Prahl (Ed.): Integrative Computational Materials Engineering, Wiley-VCH Verlag GmbH & Co. KGaA, 2012, ISBN 978-3-527-33081-2

A Proof for the Possibility of Ce-Oxide from CMP Residuals in Si-Wafers by Analytical TEM

2012 ◽  
Author(s):  
Wayne Zhao ◽  
Liem Do Thanh ◽  
Michael Gribelyuk ◽  
Mary-Ann Zaitz ◽  
Wing Lai
Keyword(s):  
Technology Development ◽  
Early Stage ◽  
Chemical Mechanical Planarization ◽  
Particle Cluster ◽  
Limited Region ◽  
Physical Evidence ◽  
Analytical Tem ◽  
Transmission Electron ◽  
Oxide Particles

Abstract Inclusion of cerium (Ce) oxide particles as an abrasive into chemical mechanical planarization (CMP) slurries has become popular for wafer fabs below the 45nm technology node due to better polishing quality and improved CMP selectivity. Transmission electron microscopy (TEM) has difficulties finding and identifying Ce-oxide residuals due to the limited region of analysis unless dedicated efforts to search for them are employed. This article presents a case study that proved the concept in which physical evidence of Ce-rich particles was directly identified by analytical TEM during a CMP tool qualification in the early stage of 20nm node technology development. This justifies the need to setup in-fab monitoring for trace amounts of CMP residuals in Si-based wafer foundries. The fact that Cr resided right above the Ce-O particle cluster, further proved that the Ce-O particles were from the wafer and not introduced during the sample preparation.

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