5 results listed
Corrax steel belong to the PH martensitic stainlesssteel family and it’s mechanical specifications and chemical
composition are similar with PH 13-8 Mo. PH steels offer to the
users high strength and hardness through precipitation
hardening. The high specifications and high ductility of this steel
make it hard to machine. Especially high ductility causes
lamellar and continuous chip formation in machining. This type
of chips coils up to the workpiece and cause surface defections on
the workpiece surface. This study investigated the different chip
formations in orthogonal machining of Corrax Steel. Results
shows the high cutting speeds and high feed rates breakes the
chips instead of low cutting speeds and low feed rates.
International Iron & Steel Symposium
UDCS
Ahmet Serdar Güldibi
Halil DEMİR
Laser cutting is a technology that has added
innovation to the industry with its precise and fast processing
capabilities. The parameters used in laser cutting processes have
effects on material cutting quality and thickness. In this study,
AISI 304 stainless steel sheet metals were cut in different focus,
nozzle, cutting speed, sheet thickness and gas pressures, and their
effects on surface roughness and cutting thickness were
investigated. According to the results, changes in the surface
roughness values were obtained by changing the parameters. It
was observed that the increased cutting speed improved the
surface roughness, but the thick materials could not be cut at
high speeds.
International Iron & Steel Symposium
UDCS
Ahmet Serdar Güldibi
Halil DEMİR
Hasan Basri UlaĢ
In this study, machinability tests were carried out on
Toolox 44 hot work tool steel (44 HRC) an important material in
developing industry. The tests were carried out dry through
milling method at four different cutting speeds (150, 180, 210, and
240 m/min), four different feed rates (0.4, 0.8, 1.2 and 1.6
mm/tooth) and at two different depth of cut (0.2 and 0.4 mm).
Cutting forces developed during milling and surface roughness of
the machined surfaces were measured. The results showed that
increasing feed rate increased the surface roughness while
increasing cutting speed decreased the cutting forces. The lowest
surface roughness value (0.533 μm) was obtained at 180 m/min
cutting speed, 0.4 mm/tooth feed rate and 0.2 mm depth of cut
while the highest one (3.126 μm) was obtained at 180 m/min
cutting speed, 1.2 mm/tooth feed rate and 0.2 mm depth of cut.
The lowest cutting force was obtained at 0.4 mm depth of cut, 0.4
mm/tooth feed rate and 180 m/min cutting speed.
International Iron & Steel Symposium
UDCS
Rüstem BİNALİ
Halil DEMİR
İbrahim ÇİFTÇİ
In this study, machinability experiments on hardened
AISI H10A hot work tool steel with CBN inserts were performed
in dry and minimum quantity lubrication (MQL) conditions.
Hard turning experiments were conducted according to Taguchi
L9 orthogonal array. The effects of cutting parameters (cutting
speed, feed rate and depth of cut) and cutting conditions on
surface roughness were analysed. The analysis of variance
(ANOVA) in 95% confidence level was applied in order to effects
of cutting parameters surface roughness. It was observed that
average surface roughness (Ra) increased with increasing feed
rate and depth of cut in dry cutting condition with CBN inserts. In
dry and MQL cutting conditions, the most important parameter
on surface roughness were determined as depth of cut with
51.79% PCR and 69.68% PCR, respectively.
International Iron & Steel Symposium
UDCS
Rıfat Akdere
Halil DEMİR
Gültekin Uzun
Mustafa GÜNAY
Genel olarak üç boyutlu (3D) yazdırma veya hızlı prototipleme olarak bilinen eklemeli imalat (AM),
1980'lerin sonlarından beri kullanılmaktadır. 3D yazdırma teknolojisindeki gelişmeler, 4D yazdırma
adı verilen yeni ve heyecan verici bir teknolojinin geliştirilmesine yol açmıştır. 4D yazdırma, dış
uyarıcılara yanıt veren önceden programlanmış “akıllı malzeme” kullanımı ile sağlanır. Bu, “4D
yazdırma” olarak bilinir ve dördüncü boyutta zamana atıfta bulunur. Akıllı malzemelerin piyasaya
sürülmesiyle, imal edilmiş bileşenler, uygulanan dış uyarıcılara bir cevap olarak zaman içerisinde
şeklini veya özelliklerini değiştirebilir. Bu çalışmada, ilk önce 3D ve 4D yazdırma hakkında genel
bilgi verilmiştir. Daha sonra 4D yazdırmadaki son teknolojik gelişmeler, yöntemler, akıllı malzemeler
ve bunların uygulamalarına odaklanarak özetlenmiştir. Sonuç olarak akıllı malzemelerin güncel
gelişmeleri ve uygulamaları ile 4D yazdırma teknolojisindeki kullanımı genel olarak ele alınmıştır. Additive manufacturing (AM), commonly known as three-dimensional (3D) printing or rapid
prototyping, has been introduced since the late 1980s. The developments of 3D printing technology
have led to the development of an exciting new technology called 4D printing. 4D printing enables
the use of ‘smart materials’ that can transform in a pre-programmed way in response to an external
stimuli. This is known as ‘4D printing’, with the fourth dimension referring to time. With the
introduction of smart materials, the AM- fabricated components are able to alter their shape or
properties over time as a response to the applied external stimuli. In this review, we first overview of
3D and 4D printing. We then summarize recent technological advances in 4D printing with focuses on
methods, smarts materials, and their applications. This paper overviews the current developments and
applications of smart materials and its use in 4D printing technology.
International Congress on 3D Printing (Additive Manufacturing) Technologies and Digital Industry
3D-PTC2019
Mehmet BOY
Halil DEMİR
Serhat Orkun TAN