Investigation of parameters affecting the formation of the bushing and bushing wall obtained in the friction drilling process

Friction drilling is an important non-traditional manufacturing method with the effect of heat caused by friction on a work piece-tool interface with a rotating tool. The purpose of this method is to increase the length of the connection through the bushing formed in the lower part of the hole in the thin-walled sheets. In this study, it is aimed to investigate the effects of material thickness and tool diameter on bushing height (ha), bushing wall thickness (hç) and micro hardness change in friction drilling method. In experiment studies, tungsten carbide (WC) tools were used with taper angle of φ=36°, the tool diameters of Ød=5 mm, Ød=10 mm, Ød=15 mm and Ød=20 mm. Friction drilling was applied to St37 steel with a thickness of t=2 mm, t=4 mm, t=6 mm, t=8 mm and t=10 mm. The experiments were carried out at a speed of n=1120 rpm and a feed rate of f=25 mm/min. The effects of material thickness and tool diameter on bushing height, bushing outer diameter, bushing shapes and changes in micro hardness were investigated. The largest bushing height of ha=15.30 mm, the lowest bushing wall thickness of hç=4.25 mm and the highest micro hardness of 183 HV was obtained. It was observed that material thickness and tool diameter had a significant effect on bushing wall thickness and bushing height, but micro hardness values did not change much.

Sürtünmeli Delme Ýþleminde Elde Edilen Kovanýn ve Pulun Oluþmasýna Etki Eden Parametrelerin Araþtýrýlmasý

Sürtünmeli delme, dönen bir takým ile iþ parçasý-takým ara yüzeyinde sürtünme sonucu oluþan ýsýnýn etkisiyle geleneksel olmayan önemli bir imalat yöntemidir. Bu yöntemin amacý, ince cidarlý saclarda, deliðin alt kýsmýnda meydana gelen kovan aracýlýðýyla baðlantý uzunluðunun arttýrýlmasýdýr. Bu çalýþmada, sürtünmeli delme yönteminde malzeme kalýnlýðýnýn ve takým çapýnýn elde edilen kovan yüksekliðine (ha), kovan çeper kalýnlýðýna (hç) ve mikro sertlik deðiþimine etkilerinin araþtýrýlmasý amaçlanmaktadýr. Deney çalýþmalarýnda, koniklik açýsý φ=36°, çaplarý Ød=5 mm, Ød=10 mm, Ød=15 mm ve Ød=20 mm olan tungsten karbür (WC) takýmlar kullanýlmýþtýr. Sürtünmeli delme iþlemleri kalýnlýðý t=2 mm, t=4 mm, t=6 mm, t=8 mm ve t=10 mm olan St37 çeliðine uygulanmýþtýr. Deney çalýþmalarý, devir sayýsý n=1120 d/d, ilerleme miktarý f=25 mm/dak þartlarýnda yapýlmýþtýr. Malzeme kalýnlýðý ve takým çapýnýn, kovan yüksekliði, kovan dýþ çapý ve kovan biçimleri üzerindeki etkileri araþtýrýlmýþ ve mikro sertlikte meydana gelen deðiþiklikler incelenmiþtir. En ideal kovan yüksekliði ha=15.30 mm, en ideal kovan çeper kalýnlýðý hç=4.25 mm ve en yüksek mikrosertlik deðeri ise 183 HV olarak elde edilmiþtir. Malzeme kalýnlýðý ve takým çapýnýn kovan çeper kalýnlýðý ve kovan yüksekliði üzerinde önemli bir etkisinin olduðu, ancak mikro sertlik deðerlerinin fazla deðiþmediði gözlenmiþtir.