Investigation of The Effects of Processing Parameters on Measuring Accuracy in Electro Erosion Machining of Ti-6Al-4V Alloy

Abstract

Titanium alloys are one of the materials that are difficult to process due to their high strength, high hardness and low thermal conductivity, wherefore low tool life and surface quality and high energy consumption are involved in shaping them with traditional manufacturing methods. In particular, special tool geometries are required for the machining of complex geometry parts including helical groove, keyseat, micro-holes, etc. with traditional manufacturing methods, which leads to increases in machining costs. In such cases, non-traditional alternative processing methods are preferred. In this study, keyseat shaping procedures were performed according to DIN 6885 standard in the electro (die-sinking) erosion machine for Ti-4Al-6V alloy. As a result of experiments conducted in copper electrode and Belone EDM F dielectric fluid environment, the effects of different processing parameters (discharge current, pulse on time and pulse off time) on measuring accuracy were investigated. In addition, the effects of 3D surface and SEM images and processing parameters on the accuracy of the coordinate measurement were evaluated. With the low discharge current, less thermal energy is transferred to the workpiece and smaller particles are removed from the workpiece, obtained in closer results to the targeted values. The biggest difference between the targeted keyseat depth, width and length and the measured value was 18.13%, 4.24% and 0.625%, respectively. The results closest to the specified standard keyseat dimensions were obtained in Ip=9A, Ton=150μs, Toff=120μs processing parameters.

Keywords

• Electro erosion machining
• Ti-6Al-4V alloy
• keyseat
• measurement accuracy

References

1. [1] Shokrani A, Dhokia V, Newman ST. Environmentally conscious machining of difficult-to-machine materials with regard to cutting fluids. International Journal of Machine Tools and Manufacture. 2012; 57: 83–101.
2. [2] Sivakumar K, Mathan Kumar P, Amarkarthik A, Jegadheeswaran S, Shanmugaprakash R. Empirical modeling of material removal rate and surface roughness of OHNS steel using Cu-TiB2Tool in EDM. Materials Today: Proceedings. 2021; 45: 2725–2729.
3. [3] Matoorian P, Sulaiman S, Ahmad MMHM. An experimental study for optimization of electrical discharge turning (EDT) process. Journal Of Materials Processing Technology. 2008; 204: 350–356.
4. [4] Pant P, Bharti PS. Electrical Discharge Machining (EDM) of nickel-based nimonic alloys: A review. Materials Today: Proceedings. 2020; 25: 765–772.
5. [5] Bishnoi P, Sahu M. Optimization of the Keyseat Design with Consideration of Effect of Stress Concentration on Different Materials. International Journal of Engineering Research & Technology. 2014; 3: 477–481.
6. [6] Kishor HP, Raghu T. Desıgn Analysıs of A Keyless Couplıng. International Journal of Recent Research in Civil and Mechanical Engineering. 2014; 1: 37–43.
7. [7] Verma V, Sajeevan R. Multi Process Parameter Optimization of Diesinking EDM on Titanium Alloy (Ti6Al4V) Using Taguchi Approach. Materials Today: Proceedings. 2015; 2: 2581–2587.
8. [8] Klocke F, Mohammadnejad M, Holsten M, Ehle L, Zeis M, Klink A. A Comparative Study of Polarity-related Effects in Single Discharge EDM of Titanium and Iron Alloys. Procedia CIRP. 2018; 68: 52–57.

9. [9] Bhaumik M, Maity K. Effect of different tool materials during EDM performance of titanium grade 6 alloy. Engineering Science and Technology, An International Journal. 2018; 21: 507–516.
10. [10] Singh NK, Singh Y, Sharma A, prasad R. Experimental investigation of flushing approaches on EDM machinability during machining of titanium alloy. Materials Today: Proceedings. 2021; 38: 139–145.
11. [11] Prakash J, Equbal MdI, Equbal A. Investigative study on dimensional accuracy of machined cavity formed during EDM of AISI 1035. Materials Today: Proceedings. 2021; 47: 3217–3220.
12. [12] Kumar P, Dewangan S, Pandey C. Analysis of surface integrity and dimensional accuracy in EDM of P91 steels. Materials Today: Proceedings. 2020; 33: 5378–5383.
13. [13] Sanchez JA, Lopez de Lacalle LN, Lamikiz A, Bravo U. Dimensional accuracy optimisation of multi-stage planetary EDM. International Journal of Machine Tools and Manufacture. 2002; 42: 1643–1648.
14. [14] Çakıroğlu R, Günay M. Comprehensive analysis of material removal rate, tool wear and surface roughness in electrical discharge turning of L2 tool steel. Journal Of Materials Research and Technology. 2020; 9: 7305–7317.
15. [15] Singh H, Shukla DK. Optimizing electric discharge machining parameters for tungsten-carbide utilizing thermo-mathematical modelling. International Journal of Thermal Sciences. 2012; 59: 161–175.
16. [16] Unses E, Çoğun C. Improvement of Electric Discharge Machining (EDM) Performance of Ti-6Al-4V Alloy with Added Graphite Powder to Dielectric. Strojniski Vestnik - Journal of Mechanical Engineering. 2015; 61.
17. [17] Azhiri RB, Bideskan AS, Javidpour F, Tekiyeh RM. Study on material removal rate, surface quality, and residual stress of AISI D2 tool steel in electrical discharge machining in presence of ultrasonic vibration effect. The International Journal of Advanced Manufacturing Technology. 2019; 101: 2849–2860.
18. [18] Koenig W. The Flow Fields in the Working Gap with Electro Discharge Machining. Annals Of The CIRP. 1977; 25: 71–75.
19. [19] Schumacher BM. About the Role of Debris in the Gap During Electrical Discharge Machining. CIRP Annals. 1990; 39: 197–199.
20. [20] Obara H, Abe M, Ohsumi T. Control of Wire Breakage during Wire EDM -1st Report: Monitoring of Gap Signals According to Discharged Location. International Journal of Electrical Machining. 1999; 4: 53–58.
21. [21] Cakiroglu R, Günay M. Elektro Erozyonla Tornalama Yöntemiyle İşlenen Soğuk İş Takım Çeliğinin Yorulma Ömrünün Tahmini. Politeknik Dergisi. 2021; 24: 495–502.