Abstract
Bu çalışmada Ti6Al4V alaşım çifti Ag ara tabaka kullanılarak difüzyon kaynak yöntemiyle birleştirilmiş ve
kaynak sıcaklığının bağlantı üzerindeki etkisi incelenmiştir. Günümüzde metal-malzeme endüstrisinde Ti’nin
kullanım alanları da artmaktadır. Titanyum yüksek derecede şekillendirilebilirlik özelliğine sahip, düşük
yoğunluklu (4.54 gr/cm3) bir elementtir. Manyetik olmayan Ti, çeliklerden daha yüksek ergime derecesine de
sahiptir. Ti ve alaşımlarının sahip olduğu yüksek dayanım, iyi tokluk, düşük yoğunluk, biyouyum ve iyi
korozyon dayanımı gibi özelliklerinden dolayı uzay endüstrisi ve yüksek performansın gerekli olduğu
uygulamalarda oldukça fazla kullanım alanına sahiptir. Bu nenenle çalışmamızda Ti alaşımlarından yaygın
olarak kullanılan Ti6Al4V alaşımı kullanılmıştır. Çalışmada difüzyon kaynakları, özel olarak hazırlanmış
difüzyon kaynak aparatında 5 MPa sabit kaynak basıncı, 60 dk’lık sabit kaynak süresi ve 750-850 ve 950
°C’lik sıcaklıklarda argon atmosferinde yapılmıştır. Kaynak sıcaklığı değişken parametre olarak seçilmiştir.
Kaynak sonrası birleşme ara yüzeyinde meydana gelen mikro yapı değişiklikleri optik mikroskop yardımıyla
incelenmiş ve kaynak ara yüzeyindeki element geçişleri için EDS analizi ve olası fazların tayini için XRD
analizi yapılmıştır. Ayrıca kaynak ara yüzeyindeki sertlik değişimini gözlemlemek amacıyla numunelere
mikrosertlik testi uygulanmıştır. Yapılan deney ve incelemeler sonrasında bütün kaynaklı numunelerde,
bağlantısız bölgelere rastlanmamıştır. Artan süreye paralel olarak daha iyi bir kaynaklı bağlantının elde
edildiği gözlenmiş ve en iyi bağlantı kalitesinin 950 °C sıcaklıkta kaynak yapılan S3 numunesinde olduğu
belirlemiştir.
Keywords
Abstract
In this study, pair of Ti6Al4V alloy joined by
diffusion welding method using Ag interlayer and
the effect on the connections of the welding
temperature was investigated.
Today, a Ti areas increase on metal- materials
industry. Titanium is an element that has high
degree of formability property, low density (4.54 g /
cm3). Non-magnetic Ti has a higher melting
temperature than steel. Ti and its alloys to have high
strength, good toughness, low density,
biocompatibility and good corrosion resistance
properties, such as the due to the space industry and
has considerable utility in applications where high
performance is required. Therefore, the present
study has been used widely used alloy of Ti Ti6Al4V
alloy.
Studies showed that the resultant joints were
composed of Ti substrate, Ti-Ag sold solution. TiAg
intermetallic phase, the remnant Ag interlayer,
indicating that the TiAg intermetallic phase exhibits
no detrimental effect on the strength of the joints.
Therefore Ag interlayer is used as an interlayer.
Diffusion bonding facilitates the joining of materials
to produce components with no abrupt discontinuity
in the microstructure and with a minimum of
deformation. The process depends on a number of
parameters, in particular, bonding temperature,
atmosphere, time, pressure, and surface roughness.
General alloying problems (brittle phase formation
and limited mutual solubility), large difference
between the melting points, the differences in
thermal conductivity of parent metals, the carbon
migration and oxidation are known as principal
factors influencing joint integrity of dissimilar metal
fusion welding. Within the confines of diffusion
bonding mechanism, problems of fusion welding as
previously indicated, can be eliminated in dissimilar
metal joints. Most combinations of dissimilar metals
can be joined by solid-state bonding methods
although the alloying between these metals is
insignificant.
In the study, diffusion welding was carried out
diffusion welding apparatus that specially designed
constant bonding pressure of 5 MPa, 60 min at
constant time and at 750-850 and 950 °C
temperature on argon atmosphere. Bonding
temperature is chosen as variable parameter.
Welding pressure and welding time is kept constant
.Samples were kept in the furnace until the furnace
temperature drops to 250 °C, then they were kept at
room temperature until cool.
Furthermore microhardness test was applied in
order to observe the changes in the interface to the
samples. In order to see the hardness changes in
bonding interfaces, sample No. S3 device with Leica
MHF-10 (0.05 HV) under 50 g load, hardness
measurements were carried out at 50 µm range
Microstructure changes that occurred after welding
were examined by optical microscope and EDS
analysis were performed for element transition in
source interface and the determination possible gas.
After originated from experiments and
investigations, it was observed in all samples of the
unrelated. Better than a welded joint in parallel with
increased duration was seen to be achieved and has
determined that the best connection quality of
welded S3 samples that was welding 950 °C
temperature. Ag diffusion was observed at rates
ranging between 100-140μm towards on the main
material for all sample. Ti86Ag7, Ti516Al65Ag78V19,
Ti8AgTi10Ag, Ti35Al4Ag4V, Ti463Al53Ag25V19,
Ti8Ag and Ti66Al17phases were found to be
intense in all specimens according to XRD
analysis.
Details
| Other ID | JA78UV99SC |
|---|---|
| Journal Section | Articles |
| Authors | |
| Publication Date | December 1, 2016 |
| Submission Date | December 1, 2016 |
| Published in Issue | Year 2016 Volume: 7 Issue: 3 |