scholarly journals Metallurgical and Machinability Characteristics of Wrought and Selective Laser Melted Ti-6Al-4V

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Manikandakumar Shunmugavel ◽  
Ashwin Polishetty ◽  
Junior Nomani ◽  
Moshe Goldberg ◽  
Guy Littlefair

This research work presents a machinability study between wrought grade titanium and selective laser melted (SLM) titanium Ti-6Al-4V in a face turning operation, machined at cutting speeds between 60 and 180 m/min. Machinability characteristics such as tool wear, cutting forces, and machined surface quality were investigated. Coating delamination, adhesion, abrasion, attrition, and chipping wear mechanisms were dominant during machining of SLM Ti-6Al-4V. Maximum flank wear was found higher in machining SLM Ti-6Al-4V compared to wrought Ti-6Al-4V at all speeds. It was also found that high machining speeds lead to catastrophic failure of the cutting tool during machining of SLM Ti-6Al-4V. Cutting force was higher in machining SLM Ti-6Al-4V as compared to wrought Ti-6Al-4V for all cutting speeds due to its higher strength and hardness. Surface finish improved with the cutting speed despite the high tool wear observed at high machining speeds. Overall, machinability of SLM Ti-6Al-4V was found poor as compared to the wrought alloy.

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 556 ◽  
Author(s):  
D. Martinez Krahmer ◽  
S. Hameed ◽  
A. J. Sánchez Egea ◽  
D. Pérez ◽  
J. Canales ◽  
...  

Free-cutting steels are developed to produce large quantities of parts with low mechanical behavior, mainly for automotive sector. These alloys contain phosphorous, lead, sulfur, and manganese that help to improve the machinability and surface roughness. However, due to the toxicity of lead, steel mills in recent years have been focusing on non-toxic steels to produce minimum environmental pollution and better machinability. The present work investigates the tool wear during dry and wet turning of free-cutting steels (SAE 1212, SAE 12L14, and SAE 1215) by using uncoated hard metal inserts at three cutting speeds. Additionally, a EDS analysis was performed to determine the presence of Mn and S elements at the rake face of the cutting tool that can induce a higher adhesion of manganese sulfide (MnS). The results show that the SAE 12L14 steel has the best performance in terms of tool life at different cutting speeds. This difference is maximum at the lowest cutting speed, which gradually decreases with the increase of the cutting speed. The wear behavior is evaluated in the three steel alloys at each cutting speed and, consequently, the tool wear exhibits a slightly better performance in the dry machining condition for higher cutting speeds (180 and 240 m/min), independent of the steel alloy. Finally, EDS analysis confirms the presence of Mn and S elements at the rake face of the inserts machined in dry condition. Hence, MnS is expected to interpose between the machined surface and cutting tool surface to behave similar to tribofilm by reducing the wear on the cutting edge.


Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.


2012 ◽  
Vol 723 ◽  
pp. 365-370 ◽  
Author(s):  
Rong Bian ◽  
Eleonora Ferraris ◽  
Jun Qian ◽  
Dominiek Reynaerts ◽  
Liang Li ◽  
...  

This work presents an experimental investigation on micro-milling of fully sintered Zirconia (ZrO2) by diamond coated tools. The experiments were conducted on a Kern MMP 2522 micro-milling centre and WC micro end mills, diamond coated by chemical vapour deposition (CVD) and of stiff geometry were employed as cutting tools. The effects of cutting parameters and milling time on tool wear were investigated. The results revealed that the tool wear characters included diamond coating delamination and wear of substrate WC. Both cutting forces and machined surface quality were affected by tool wear with the progress of milling.


2013 ◽  
Vol 685 ◽  
pp. 68-75 ◽  
Author(s):  
Salman Pervaiz ◽  
Ibrahim Deiab ◽  
Basil Darras ◽  
Amir Rashid ◽  
Mihai Nicolescu

Titanium alloys are labeled as difficult to materials because of their low machinability rating. This paper presents an experimental study of machining Ti-6Al-4V under turning operation. All machining tests were conducted under dry, mist and flood cooling approaches by using a TiAlN coated carbide cutting inserts. All cutting experiments were conducted using high and low levels of cutting speeds and feed rates. The study compared surface finish of machined surface and flank wear at cutting edge under dry, mist and flood cooling approaches. Scanning electron microscopy was utilized to investigate the flank wear at cutting edge under various cooling approaches and cutting conditions. Investigation revealed that TiAlN coated carbides performed comparatively better at higher cutting speed.


2020 ◽  
Vol 21 (2) ◽  
pp. 177-185
Author(s):  
Natasha A. Raof ◽  
Nur Sofwati Daud @Ab Aziz ◽  
Abdul Rahman A. Ghani ◽  
Aishah Najiah Dahnel ◽  
Suhaily Mokhtar ◽  
...  

 Recently, almost 70% of a commercial jetliner’s airframe is made of aluminium alloys. It is predicted that the application of aluminium alloy is to increase up to 65% by the year 2025. They are typically used because of their high strength to weight ratio. However, there are some drawbacks during machining aluminium alloy such as the adhesion wear and built-up edge (BUE) formation that can shorten tool life. As the tool wears, the machining performance, surface roughness, and cutting tool life are affected significantly. A lot of studies were conducted in order to minimize this critical issue. This project presents a study of the cutting tool performance of an uncoated carbide tool in dry turning operation on Al 7075-T651, in which the tool wear rate, volume of material removed, wear mechanism, and surface roughness were investigated. The machining tests were conducted on a CNC lathe machine to obtain the tool wear and surface roughness of the machined work piece. The average flank wear was measured using a digital microscope, whereas the wear mechanism was observed using a Scanning Electron Microscope (SEM). The average surface roughness (Ra) was measured using a surface roughness tester. The cutting time for this experiment was fixed at 40 minutes and all the results were analysed within this time range to evaluate the tool performance in the turning of Al 7075-T651. The results revealed that the tool performs better at low cutting speed, 250 m/min, by reducing the tool wear rate by 33%. The cutting speed of 250 m/min also contributed to 71% higher volume of material removed during the machining tests. The dominant type of wear found was flank wear, while the main principal of wear mechanism is adhesion. At higher cutting speed, the surface roughness was improved. Based on the results, it can be concluded that high cutting tool performance is achieved when low tool wear growth rate, high volume of material removal, and low surface roughness during turning operation are obtained. ABSTRAK: Kebelakangan ini, hampir 70% kerangka pesawat udara komersil diperbuat daripada aloi aluminium. Penggunaan aloi aluminum ini dijangka meningkat sehingga 65% pada tahun 2025. Ia biasa digunakan kerana nisbah kekuatan kepada berat yang tinggi. Walau bagaimanapun, terdapat beberapa kekurangan semasa pemesinan aloi aluminum ini iaitu pemakaian pelekat dan pembentukan binaan tepi (BUE) yang mengurangkan jangka hayat mata alat. Apabila mata alat menjadi haus, prestasi mesin, kekasaran permukaan, dan jangka hayat mata alat pemotong terjejas dengan ketara. Banyak kajian telah dijalankan bagi mengurangkan isu kritikal ini. Projek ini mengkaji prestasi mata alat pemotong karbida tidak bersalut dalam operasi mesin larik kering pada Al 7075-T651, di mana kadar haus mata alat, kuantiti bahan yang dibuang, mekanisme haus dan kekasaran permukaan telah diselidiki. Ujian pemesinan dijalankan pada mesin CNC mesin larik bagi mendapatkan kadar haus mata alat dan kekasaran permukaan material yang dimesin. Purata haus pengapit mata alat diukur dengan menggunakan mikroskop digital, manakala mekanisme haus dipantau menggunakan Mikroskop Elektronik Pengimbas (SEM). Purata kekasaran permukaan (Ra) diukur menggunakan alat penguji kekasaran permukaan. Tempoh masa pemotongan bagi eksperimen ini telah ditetapkan pada 40 minit dan semua keputusan telah dianalisa dalam tempoh masa ini bagi menilai prestasi mata alat dalam melarik Al 7075-T651. Hasil menunjukkan prestasi mata alat lebih baik pada kelajuan pemotongan rendah, 250 m/min dengan mengurangkan kadar haus mata alat sehingga 33%. Kelajuan pemotongan 250 m/min juga menyumbang kepada 71% peningkatan ke atas jumlah bahan yang dibuang semasa ujian pemesinan. Jenis haus yang dominan telah ditemui pada pengapit mata alat, manakala mekanisme haus yang utama adalah lekatan. Pada kelajuan pemotongan yang tinggi, kekasaran permukaan didapati lebih baik. Berdasarkan keputusan, dapat disimpulkan bahawa prestasi mata alat pemotong yang bagus dapat dicapai apabila kadar haus mata alat adalah rendah, jumlah penyingkiran bahan yang tinggi dan kekasaran permukaan yang rendah semasa operasi pelarikan dijalankan. ABSTRAK: Kebelakangan ini, hampir 70% kerangka pesawat udara komersil diperbuat daripada aloi aluminium. Penggunaan aloi aluminum ini dijangka meningkat sehingga 65% pada tahun 2025. Ia biasa digunakan kerana nisbah kekuatan kepada berat yang tinggi. Walau bagaimanapun, terdapat beberapa kekurangan semasa pemesinan aloi aluminum ini iaitu pemakaian pelekat dan pembentukan binaan tepi (BUE) yang mengurangkan jangka hayat mata alat. Apabila mata alat menjadi haus, prestasi mesin, kekasaran permukaan, dan jangka hayat mata alat pemotong terjejas dengan ketara. Banyak kajian telah dijalankan bagi mengurangkan isu kritikal ini. Projek ini mengkaji prestasi mata alat pemotong karbida tidak bersalut dalam operasi mesin larik kering pada Al 7075-T651, di mana kadar haus mata alat, kuantiti bahan yang dibuang, mekanisme haus dan kekasaran permukaan telah diselidiki. Ujian pemesinan dijalankan pada mesin CNC mesin larik bagi mendapatkan kadar haus mata alat dan kekasaran permukaan material yang dimesin. Purata haus pengapit mata alat diukur dengan menggunakan mikroskop digital, manakala mekanisme haus dipantau menggunakan Mikroskop Elektronik Pengimbas (SEM). Purata kekasaran permukaan (Ra) diukur menggunakan alat penguji kekasaran permukaan. Tempoh masa pemotongan bagi eksperimen ini telah ditetapkan pada 40 minit dan semua keputusan telah dianalisa dalam tempoh masa ini bagi menilai prestasi mata alat dalam melarik Al 7075-T651. Hasil menunjukkan prestasi mata alat lebih baik pada kelajuan pemotongan rendah, 250 m/min dengan mengurangkan kadar haus mata alat sehingga 33%. Kelajuan pemotongan 250 m/min juga menyumbang kepada 71% peningkatan ke atas jumlah bahan yang dibuang semasa ujian pemesinan. Jenis haus yang dominan telah ditemui pada pengapit mata alat, manakala mekanisme haus yang utama adalah lekatan. Pada kelajuan pemotongan yang tinggi, kekasaran permukaan didapati lebih baik. Berdasarkan keputusan, dapat disimpulkan bahawa prestasi mata alat pemotong yang bagus dapat dicapai apabila kadar haus mata alat adalah rendah, jumlah penyingkiran bahan yang tinggi dan kekasaran permukaan yang rendah semasa operasi pelarikan dijalankan.


2021 ◽  
Author(s):  
Raqibah Najwa Mudzaffar ◽  
Mohamad Faiz Izzat Bahauddin ◽  
Hanisah Manshor ◽  
Ahmad Zahirani Ahmad Azhar ◽  
Nik Akmar Rejab ◽  
...  

Abstract The zirconia toughened alumina enhanced with titania and chromia (ZTA-TiO2-Cr2O3) ceramic cutting tool is a new cutting tool that possesses good hardness and fracture toughness. However, the performance of the ZTA-TiO2-Cr2O3 cutting tool continues to remain unknown and therefore requires further study. In this research, the wearing of the ZTA-TiO2-Cr2O3 cutting tool and the surface roughness of the machined surface of stainless steel 316L was investigated. The experiments were conducted where the cutting speeds range between 314 to 455 m/min, a feed rate from 0.1 to 0.15 mm/rev, and a depth of cut of 0.2 mm. A CNC lathe machine was utilised to conduct the turning operation for the experiment. Additionally, analysis of the flank wear and crater wear was undertaken using an optical microscope, while the chipping area was observed via scanning electron microscopy (SEM). The surface roughness of the machined surface was measured via portable surface roughness. The lowest value of flank wear, crater wear and surface roughness obtained are 0.044 mm, 0.45 mm2, and 0.50 µm, respectively at the highest cutting speed of 455 m/min and the highest feed rate of 0.15 mm/rev. The chipping area became smaller with the increase of feed rate from 0.10 to 0.15 mm/rev and larger when the feed rate decrease. This was due to the reduced vibrations at the higher spindle speed resulting in a more stable cutting operation, thereby reducing the value of tool wear, surface roughness, and the chipping area.


Author(s):  
Shoujin Sun ◽  
Milan Brandt ◽  
Matthew S Dargusch

Variation in the geometric and surface features of segmented chips with an increase in the volume of material removed and tool wear has been investigated at cutting speeds of 150 and 220 m/min at which the cutting tools fail due to gradual flank wear and plastic deformation of the cutting edge, respectively. Among the investigated geometric variables of the segmented chips, slipping angle, undeformed surface length, segment spacing, degree of segmentation and chip width showed the different variation trends with an increase in the volume of material removed or flank wear width, and achieved different values when tool failed at different cutting speeds. However, the chip geometric ratio showed a similar variation trend with an increase in the volume of material removed and flank wear width, and achieved the similar value at the end of tool lives at cutting speeds of both 150 and 220 m/min regardless of the different tool failure modes. Plastic deformation of the tool cutting edge results in severe damage on the machined surface of the chip and significant compression deformation on the undeformed surface of the chip.


2015 ◽  
Vol 12 (2) ◽  
pp. 5-9
Author(s):  
Karol Vasilko

Abstract Beside cutting speed, shift is another important parameter of machining. Its considerable influence is shown mainly in the workpiece machined surface microgeometry. In practice, mainly its combination with the radius of cutting tool tip rounding is used. Options to further increase machining productivity and machined surface quality are hidden in this approach. The paper presents variations of the design of productive cutting tools for lathe work and milling on the base of the use of the laws of the relationship among the highest reached uneveness of machined surface, tool tip radius and shift.


Here, we found and observed different results of experimental work in dry turning of S31700 grade stainless steels using coated and uncoated cemented carbides. The turning tests were conducted at three different cutting speeds (150and 200m/min) while feed rate and depth of cut were kept constant at 0.3 mm/rev and 1 mm, respectively. The cutting tools used were ISO P30 uncoated and TiN-TiCN-Al2O3 -ZrCN coated cemented carbides. We found the influences of cutting speed on the average flank wear. The worn parts of the cutting tools were also examined using optical microscopy and SEM. Here we concluded that cutting speed significantly affected the average flank wear. The multilayer effects superior resistance to tool wear compared to its uncoated counterpart in the entire range of cutting speeds during turning of S31700 stainless (AISI317) steel.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7128
Author(s):  
Adel T. Abbas ◽  
Essam A. Al Bahkali ◽  
Saeed M. Alqahtani ◽  
Elshaimaa Abdelnasser ◽  
Noha Naeim ◽  
...  

This paper reports a fundamental investigation consisting of systematic trials into the response of Ti6Al4V alloy to high-speed machining using carbide inserts. It is a useful extension to work previously published, and aims at assessing the impact of the process parameters, depth of cut, cutting speed and feed rate in addition to cutting length, and their interrelations, on observed crater and flank wear and roughness of the machined surface. The results showed that abrasion was the most important flank wear mechanism at high speed. It also showed that increased cutting length accelerated crater wear more than exhibited flank wear and had considerable effect on surface roughness. In particular, crater wear increased by over 150% (on average), and flank wear increased by 40% (on average) when increasing cutting length from 40 to 120 mm. However, cutting the same length increased surface roughness by 50%, which helps explain how progression of tool wear leads to deteriorated surface quality. ANOVA was used to perform statistical analyses of the measured data and revealed that cutting length and depth of cut had the greatest effect on both crater and flank wear of the cutting tool. These results confirm that high-speed machining of Ti6Al4V alloy is a reliable process, with cutting speed identified as having a relatively small influence on the tool wear and resultant roughness of the machined surface relative to other parameters.


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