Microstructure effects on process outputs in micro scale milling of heat treated Ti6Al4V titanium alloys

2018-02-01
Ahmadi, Masoud
Karpat, Yigit
ACAR, Ozgun
Kalay, Yunus Eren
Show full item record
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
247
views
21
downloads
This study investigates the influence of materials' microstructural characteristics, including grain size and phase fractions, in micro end milling of heat treated Ti6Al4V titanium alloys. Micro milling process conditions such as feed, depth of cut, and the cutting edge radius of the micro end mill are in the same order of magnitude as the grain size of the material, which gives rise to the anisotropic behavior of the multiphase materials and their deformation characteristics considering their grain size, grain boundaries, and phase fractions. A good understanding of such relationships is believed to be instrumental in developing predictive models of machining based on computational techniques. The influence of micro milling process on the crystallographic texture and microstructure of Ti6Al4V alloys is the subject of this study. For this purpose, heat treatment was performed on the Ti6Al4V samples to obtain two different microstructures: fine equiaxed and enlarged equiaxed microstructures. Micro milling experiments were performed on each sample and process outputs such as cutting forces, areal surface texture, built-up edge (BUE) formation, and alterations in the microstructure were investigated. Electron backscatter diffraction (EBSD) analysis was used to investigate the microstructure of the machined surfaces. It was observed that smaller grain size (both alpha and beta) and lower fraction of beta phase in the material yielded higher cutting forces. BUE formation and its size were affected by the microstructure of the samples. The results of this study may be useful in developing microstructure-based, predictive modeling of micro milling process.
Micro milling, Titanium alloys, EBSD analysis
https://hdl.handle.net/11511/37336
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
Department of Metallurgical and Materials Engineering, Article

Suggestions

Microstructural and texture evolution during thermo-hydrogen processing of Ti6Al4V alloys produced by electron beam melting
Dogu, Merve Nur; ESEN, ZİYA; Davut, Kemal; Tan, Evren; Gumus, Berkay; Dericioğlu, Arcan Fehmi (Elsevier BV, 2020-10-01)
The present study was conducted to reveal the effects of building angles and post heat-treatments (2-step Thermo-Hydrogen Processing (THP) and conventional annealing treatment) on the density, microstructure and texture of Ti6Al4V alloy parts produced by Electron Beam Melting (EBM). The results showed that regardless of the building angle; the density, microstructure and crystallographic texture (defined with respect to building angle) of the as-produced samples were identical; having Widmanstatten a struct...
Photocatalytic properties of silver loaded titanium dioxide powders produced by mechanical ball milling
Aysin, Başak; Öztürk, Abdullah; Park, Jongee; Department of Metallurgical and Materials Engineering (2012)
Silver (Ag) was loaded to three different kinds (P-25, NT-22, and TiO(OH)2) of titanium dioxide (TiO2) powders through adding three different quantities (4.6, 9.2, and 13.8 ml) of silver nitrate (AgNO3) solution by mechanical ball milling process. X-Ray diffraction analysis suggested that Ag was loaded on the TiO2 powders in the form of silver oxide (AgO). SEM, particle size, and BET surface area analyses revealed that TiO2 particles agglomerated after ball milling, resulting in the decrease of specific sur...
Microstructure hierarchy - Mechanical property relationship for hypereutectic Al-Si alloy powders solidified far from equilibrium
Kalay, Yunus Eren; Chumbley, L.s. (2006-12-01)
Microstructural selection in aluminum silicon powder alloys can directly influence the consolidated materials' mechanical properties. However, due to processing and characterization difficulties, a complete understanding of powder microstructure as a function of undercooling and solidification velocity, and the role microstructure plays on mechanical properties, remains an elusive goal. In this study high pressure gas atomization processing was used to produce rapidly solidified hypereutectic Al-Si alloys. ...
Micromechanical cohesive zone relations for ductile fracture
Yalçınkaya, Tuncay (Elsevier BV; 2016-06-24)
This paper addresses the derivation of a micromechanically motivated incremental mixed-mode traction separation law in the context of cohesive zone modeling of crack propagation in ductile metallic materials. The formulation is based on the growth of an array of pores idealized as cylinders which are considered as the representative volume elements. An upper bound solution is applied for the deformation of the representative volume element and different incremental traction-separation relations are obtained...
Micromechanical Modelling of Carbon Nanotube Reinforced Composite Materials with a Functionally Graded Interphase
Gülaşık, Hasan; Göktepe, Serdar; Gürses, Ercan (null; 2018-10-10)
This paper introduces a new method of determining the mechanical properties of carbon nanotube-polymer composites using a multi-inclusion micromechanical model with functionally graded phases. The nanocomposite was divided into four regions of distinct mechanical properties; the carbon nanotube, the interface, the interphase and bulk polymer. The carbon nanotube and the interface were later combined into one effective fiber using a finite element model. The interphase was modelled in a functionally graded m...
Citation Formats
M. Ahmadi, Y. Karpat, O. ACAR, and Y. E. Kalay, “Microstructure effects on process outputs in micro scale milling of heat treated Ti6Al4V titanium alloys,” JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, pp. 333–347, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37336.
METU IIS - Integrated Information Service open@metu.edu.tr