INVESTIGATION THE MICRO HARDNESS AND MICRO STRUCTURE IN FRICTION DRILLING

Abstract

Friction drilling process is a non-traditional hole making method which a no-chip drilling process was formed by thermal friction. In this friction drilling experimental study, the selected spindle speeds were 2400rpm, 3600rpm, and 4800rpm, feed rates was 75mm/min and tool material were HSS and WC tools with 240, 360, and 480 conical angles and 24mm, tool cylindrical region lengths. The specimens were St37 and A7075–T651 alloys with thickness of 4mm and 6mm. It was analysed the effect of experimental parameters on the micro hardness and micro structure. Maximum micro hardness values were obtained at 3600rpm spindle speed, 360 and 480 conical angles the smaller micro hardness was obtained at 240 tool conical angle. in In friction drilling of St37 steel alloy higher micro hardness values were obtained than in friction drilling of A7075-T651 aluminium alloy. Because of deficient precipitation hardening of St37 steel alloy the micro hardness was not changed over.

Keywords

• Friction drilling, Micro hardness, Micro structure, Spindle speed, Conical angle,

SÜRTÜNMELİ DELMEDE MİKRO YAPI VE MİKRO SERTLİĞİN ARAŞTIRILMASI

Abstract

Sürtünmeli delme, geleneksel olmayan, sürtünme sonucu oluşan ısının etkisi ile delik delme yöntemidir. Bu çalışmada, 2400d/dak, 3600d/dak ve 4800d/dak dönme hızlarında, 75mm/dak ilerleme hızında, cidar kalınlığı 4mm ve 6mm olan St 37 ve A7075–T651 alaşımlarına sürtünmeli delme yöntemiyle delikler delinmiştir. Delme esnasında koniklik açısı 240, 360 ve 480, silindirik bölge uzunluğu hl=24mm olan HSS ve WC takımlar kullanılmıştır. Elde edilen deliklerin, mikro sertlik ve mikro yapı üzerindeki etkisi araştırılmıştır. Maksimum mikro sertlik değeri 3600d/dak dönme hızında, 360 ve 480 koniklik açılarında, 240 koniklik açısında ise daha düşük değerler elde edilmiştir. St37 çelik alaşımında, A7075-T651 alüminyum alaşımına göre daha yüksek mikro sertlik değerleri elde edilmiştir. St37 çelik alaşımında çökelti sertleşmesi olmadığından mikro sertlik değerinde fazla değişiklik olmamıştır.

Keywords

• Sürtünmeli Delme, Mikro sertlik, Mikro yapı, Devir sayısı, Koniklik açısı,

References

1. Miller, S.F., Tao, J., and Shih, A.J., (2006). Friction Drilling of Cast Metals, International Journal of machine Tool and Manufacture, 46, pp:1526–1535.
2. Lee, S.M., Chow, H.M., Huang, F.Y., and Yan, B.H., (2009). Friction Drilling of Austenitic Stainless Steel by Uncoated and PVD AlCrN–and TiAlN Coated Tungsten Carbide Tools, International Journal of Machine Tools and Manufacture, 49, pp:81–88.
3. Lee, S.M., Chow, H.M., Yan, B.H., (2007). Friction drilling of IN–713LC cast superalloy, Materials and Manufacturing Processes, 22, pp:893–897
4. Miller, S.F., McSpadden, S.B., Wang, H., Li, R., and Shih, A.J., (2004), Experimental and numerical analysis of the friction drilling process, ASME, Journal of Manufacturing Science and Engineering, submitted for publication.
5. Miller, S.F., Blau, P., and Shih, A.J., (2005). Microstructural Alterations Associated with Friction Drilling of Steel, Aluminum and Titanium, Journal of Materials Engineering and Performance 14 (5), pp:647–653.
6. Chow, M.H., Lee, M.S., and Yang, L.D., (2008). Machining Characteristic study of friction drilling on AISI 304 Stainless Stell, journal of Materials Processing Technology, 207, pp:180– 1
7. Miller, S.F., Blau, P.J., and Shih, A.J., (2007). Tool Wear in Friction Drilling, International journal of Machine Tools and Manufacture 47, pp:1636–1645
8. Miller, S.F., Wang, H., Li, R., and Shih, A.J., (2006). “Experimental and Numerical Analysis of the Friction Drilling Process”, Journal of Manufacturing Science and Engineering 128 (3), 802–810.

9. Miller, S.F. and Shih, A.J., Therno–Mechanical Finite Element Modeling of the Friction Drilling Process, International journal of Manufacturing Science and Engineering 129, pp:531–538. Gopal Krichna, P.V., Kishore, K., and Satyanarayana, V.V., (2010). Some Investigations in Friction Drilling AA6351 Using High Speed Steel Tools, ARPN Journal Engineering and Applied Sciences, 5, pp:1819–6608.
10. Miller, S.F., Blau, P.J., and Shih, A.J., (2007). Tool Wear in Friction Drilling, International of Machine Tool and manufacture, 47, pp:1636–1645.
11. Dekkers, G., (1993). Flow Drill Prosesi Firma Katalogları, Copyright by Flow Drill B.V. Holland, pp:1–30.