Effects of different friction stir welding
parameters on welding strength
Journal Name:
- Dicle Üniversitesi Mühendislik Fakültesi Mühendislik Dergisi
Keywords (Original Language):
| Author Name | University of Author | Faculty of Author |
|---|---|---|
Abstract (2. Language):
Friction stir welding is one of the continuously
developing welding type. In this study this welding
type was investigated on Al-7075-T6. This Al-Alloy
passing in front of other alloys with high technical
specifications. It has used in aerospace, military and
automotive area widely. Tungsten inert gas (TIG)
and laser welding processes decrease strength
which is one of the very important mechanical
properties.
As a solid state welding operation conducted lower
temperature than other fusion based welding types.
Welding quality is influenced by many factors.
Welding feed rate and number of revolutions are
among these factors. Therefore, Al-7075-T6
combined with friction stir welding, effectiveness of
the parameters (welding feed rate and the number of
revolutions) was investigated.
Rolled plates of 5mm thickness, Al-7075-T6 alloy
base metal, were cut to 300x100x5 mm. The welding
direction of material was normal to the rolling
direction. Non-consumable tools made of AISI H13
(4.8 mm pin length) used to fabricate the joints. The
study was conducted two different welding feed rate
(40 mm/Rev. and 70 mm/Rev.,) and two different
number of revolutions (710 rpm. and 1000 rpm.)
Totally 4 experiments were carried out with crossing
of these parameters.
Experiment carried out with an on a milling
machine (TAKSAN APS II 400 (FU 400x600 V/2)
with no-lubrication and no-cooling. Angle between
shoulder and normal direction of the plates (The tilt
angle), was selected as 2o for all the experiments.
After the joining made Welded parts are subjected to
tensile tests and bending tests in universal testing
machine (Instron 3369). For better accuracy the
tensile test and bending test was repeated three
times. Welded parts are also subjected to microhardness
measurements in the Shimadzu HMV micro
hardness device.
After the investigations results show that the parts
joint with friction stir welding were effected directly
by welding feed rate and the number of revolutions.
Joins that are performed in a low feed rate and high
tool rotation speed of progress positive effect was
observed. The highest tensile strength was obtained
by 40 mm / min. feed rate and 1000 rev / min. tool
rotation speed. The highest bending resistance
strength has been achieved by 40 mm/min. feed rate
and rev / min. tool rotation speed.
The micro hardness profiles for different welding
parameters was observed that the hardness
decreases by increasing the distance from the weld
center. Different welding parameters was showed
that no difference on welding profiles.
Some of joint was showed that a limited welding
quality. Especially 4Th part had a welding defect
(tunnel defect) that reduce mechanical properties.
Maximum welding quality was formed at the level of
65% compared to the base material.
The results showed that Friction stir welding can be
used for joint Al-7075-T6 material. Higher welding
quality can be achieved with optimum parameters.
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Abstract (Original Language):
Yapılan bu çalışmada, sürekli gelişen kaynak türlerinden olan sürtünme karıştırma kaynağının
diğer alaşımların önüne yüksek teknik özellikler ile geçen Al-7075-T6 üzerindeki etkisi
incelenmiştir. Kaynak kalitesi birçok faktörden etkilenmektedir. Kaynak hızı ve devir sayısı bu
etkenlerin arasındadır. Bu nedenle Al-7075-T6 malzemenin Sürtünme karıştırma kaynağı ile
birleştirilmesinde kaynak hızı ve devir sayısı parametrelerin etkinliği araştırılmıştır. Çalışma 40
mm/dev. ve 70 mm/dev. olmak üzere iki farklı kaynak hızı, 710 dev/dk. ve 1000 dev/dk. olmak üzere
iki farklı devir sayısı kullanılmıştır. Bu parametrelerin çaprazlanması ile toplam 4 deney
geçekleştirilmiştir. Yapılan birleştirmeler sonrası elde edilen kaynaklı parçalar çekme ve eğme
testleri ile mikro sertlik ölçümlerine tabi tutulmuştur. Yapılan incelemeler sonucunda Sürtünme
Karıştırma Kaynağı ile birleştirilen parçaların kaynak kalitesinin takım ilerleme hızı ve takım devir
sayısından doğrudan etkilendiği tespit edilmiştir.
Gerçekleştirilen birleştirmelerde düşük ilerleme hız ve yüksek takım devrinin olumlu etkisi
görülmüştür. En yüksek çekme dayanımı 40 mm/dk. ilerleme hızı ve 1000 dev/dk. takım devir ile
elde edilmiştir. Eğme dayanımında ise en yüksek dayanım 40 mm/dk. ilerleme hızı ve 710 dev/dk.
takım devri ile elde edilmiştir. Kaynak kalitesi ana malzemeye oranla %65 seviyesinde oluşmuştur.
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