Bir alüminyum alaşımı  ile basınçlı döküm yöntemi kullanılarak tabanca gövdesi  üretimi
With one of aluminum alloy  using die casting method producing gun body
Yazar: VOLKAN TOPTAŞ
Danışman: PROF. DR. EYÜP SABRİ KAYALI
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Metalurji ve Malzeme Mühendisliği Ana Bilim Dalı
Derece: Yüksek Lisans, 2014
Konu: Metalurji Mühendisliği = Metallurgical Engineering

Özet:
Alüminyum metalinin endüstrileşmesi Türkiye'de 1950'li yıllarda başladı. Alüminyum uygulamaları da 20. yüzyılın ikinci yarısında bina doğramaları (kapı, pencere), mutfak eşyaları ve elektrik enerjisi naklinde kullanılan iletkenlerin yapımı ile başladı.
Gelişmiş ülkelerle karşılaştırıldığında, alüminyumun ülkemizde göreceli olarak kısa bir geçmişi var. 1956 yılında çok küçük ve az sayıdaki atölyede 100 ton kadar alüminyum işlendiği biliyoruz. 1960'lı yıllardan itibaren özellikle dayanıklı tüketim mallarının üretimine başlanması ve otomotiv sektöründeki gelişmelerle beraber alüminyuma olan talep de artmaya başladı. 1974 yılında, bir devlet kuruluşu olan Etibank Seydişehir Alüminyum Tesisleri'nin birincil alüminyum üretimine geçmesiyle birlikte ülkemizdeki alüminyum sanayi de önemini artırmaya başladı.
70'li yılların başlarında elektrik enerjisi yetersizliği nedeniyle talebe cevap verebilecek kadar metal üretilememesi, birincil alüminyumun (hammadde) üretimini ve bu endüstrinin gelişmesini kısıtladı. Ülkemizin tek hammadde üreticisi olan bu tesisin yıllık üretim kapasitesi halen yıllık 60.000 tondur.
Alüminyum, ülkemizde çelikten sonra en çok tüketilen malzemedir. 2011 verilerine göre toplam alüminyum sektöründe faaliyet gösteren firmaların toplam üretim kapasitelerinin 1.400.000 ton civarında olduğu tahmin edilmektedir. 2008 yılı verilerine göre Türkiye'de kişi başına alüminyum tüketimi 7,8 kg iken 2011 yılında 10,5 kg seviyesine gelmiştir. Tüketimin kişi başına yılda 30 kg seviyelerine çıkmasının beklendiği göz önünde bulundurulduğunda sektörün geleceği oldukça parlak gözükmektedir.
Alüminyum başta ulaştırma, inşaat ve ambalaj sektörlerinde olmak üzere yeni teknolojilerin de etkisiyle kullanımı giderek artan bir ürün olarak 21. yüzyıl metali olarak görülmektedir. Bunların dışında otomotiv, uçak, vagon yapımı, elektrik, tel ve kablo üretimi, savunma sanayi, makine ve elemanları ile metalurji alanlarında yaygın kullanımı vardır. 
Basınçlı döküm yöntemi ise sıvı metalin basınç altında  metal kalıba doldurulması yoluyla elde edilen döküm yöntemidir. Alüminyum esaslı malzemelerin üretiminde önemli bir yere sahiptir. Dövme yöntemi ile kıyaslandığında çoklu sayıda üretilen parçalarda maliyet ve işçilikte önemli avantaj sağlayan bir döküm yöntemidir.
Bu çalışma 6082 alüminyum alaşımı ile dövme metodu ile yapılan tabanca gövdesinin uygun hammadde ile basınçlı döküm yöntemi kullanılarak üretilmesi ve incelenmesini kapsamaktadır. 
Bu amaçla öncelikle hammadde tedarikçileriyle irtibata geçilmiş olup en uygun hammadde için deneyler yapılmıştır. 6082 dövme alaşımından üretilen silah gövdesinin tüm özellikleri irdelenmiş olup buna yakın özelliklere sahip hammadde araştırımış ve basınçlı döküm ile üretilmiştir. Bu sayede hem üretim hızında artma, hem de işçilik maliyetleri azaltılması amaçlanmıştır. Parça boyutunun, ağırlığının basınçlı döküme uygun olması ve maliyette ciddi bir avantaj sağlaması üretimin planlanmasını mümkün kılmıştır.

Abstract:
In Turkey, aluminum industry starts in 1950. After that in 20. Century it's uses in door, window, kitchen appliances and electrical power system.
Comparative to other countries, Turkey have a short story about aluminum. In 1956, there are few companies and their capacities only 100 tons. After develope automotive sectors in 1960,it's cause increasing the need of aluminum. In 1974, Etibank Seydişehir Aluminum company start produce primary aluminum and aluminum indusrty develop quickly.
Beginning of the 1970's, due to lack of electricity, aluminum industries output decrease. For aluminum sector, Our country's only manufacturer of raw materials Etibank Seydişehir Aluminum companies capacity is 65.00 tons/year now. 
In our country, aluminum is the most consumed material after steel. According to 2011 data, All of companies which is in aluminum sector, their capaties about 1.400.000 tone. On the other hand, in 2008 per capita consumption of aluminum about 7,8 kg, but in 2011 this consumption is about 10,5 kg. In future aluminum consumption expect  that rise to 30 kg. 
Aluminum generally  uses transportation, building and packing sector and this use increases from year to year. Also aluminum use automobile, aircraft, electrical, cable, military, machine, metallurgy industry.
Globally, recycling of aluminium products is being emphasized as a facilitator of future growth of the industry. Products such as cans, aluminium foils, plates and automotive components can be easily recycled thereby saving energy and reducing greenhouse emissions; it is interesting to note that more than 63% of all aluminium cans are recycled worldwide. Recycling of aluminium uses only 5% of the energy required for primary production and emits just 5% of the greenhouse gases. 
Die casting equipment was invented in 1838 for the purpose of producing movable type for the printing industry. The first die casting-related patent was granted in 1849 for a small hand operated machine for the purpose of mechanized printing type production. In 1885, Otto Mergenthaler invented the linotype machine, an automated type casting device which became the prominent type of equipment in the publishing industry. The Soss die-casting machine, manufactured in Brooklyn, NY was the first machine to be sold in the open market in North America. Other applications grew rapidly, with die casting facilitating the growth of consumer goods and appliances by making affordable the production of intricate parts in high volumes. In 1966,  General Motors released the Acurad process. 
Traditionally cast in hand jerk moulds now predominantly die cast after the industrialisation of the type foundries. Around 1900 the slug casting machines came onto the market and added further automation with sometimes dozens of casting machines at one newspaper office.
Die casting method is, metal mold filled with liquid metal under pressure, obtained by the casting method. For product alumınum-based material, die casting method is very important and usefull. As compared with forging method, for to produce multiple number of material, die casting method more advantageous than the other casting methods.
The casting equipment and the metal dies represent large capital costs and this tends to limit the process to high volume production. Manufacture of parts using die casting is relatively simple, involving only four main steps, which keeps the incremental cost per item low. It is especially suited for a large quantity of small to medium sized castings, which is why die casting produces more castings than any other casting process. Die castings are characterized by a very good surface finish and dimensional consistency.
Two variants are pore-free die casting, which is used to eliminate gas porosity defects; and direct injection die casting, which is used with zinc castings to reduce scrap and increase yield.
The following are the four steps in traditional die casting, also known as high-pressure die casting, these are also the basis for any of the die casting variations: die preparation, filling, ejection, and shakeout. The dies are prepared by spraying the mold cavity with lubricant. The lubricant both helps control the temperature of the die and it also assists in the removal of the casting. The dies are then closed and molten metal is injected into the dies under high pressure; between 10 and 175 megapascals (1,500 and 25,400 psi). Once the mold cavity is filled, the pressure is maintained until the casting solidifies. 
The dies are then opened and the shot (shots are different from castings because there can be multiple cavities in a die, yielding multiple castings per shot) is ejected by the ejector pins. Finally, the shakeout involves separating the scrap, which includes the gate, runners,sprues and flash, from the shot. This is often done using a special trim die in a power press or hydraulic press. Other methods of shaking out include sawing and grinding. A less labor-intensive method is to tumble shots if gates are thin and easily broken; separation of gates from finished parts must follow. This scrap is recycled by remelting it. The yield is approximately 67%.
The high-pressure injection leads to a quick fill of the die, which is required so the entire cavity fills before any part of the casting solidifies. In this way, discontinuities are avoided, even if the shape requires difficult-to-fill thin sections. This creates the problem of air entrapment, because when the mold is filled quickly there is little time for the air to escape. This problem is minimized by including vents along the parting lines, however, even in a highly refined process there will still be some porosity in the center of the casting. 
Most die casters perform other secondary operations to produce features not readily castable, such as tapping a hole, polishing, plating, buffing, or painting.
Aluminium alloy 6082 is a medium strength alloy with excellent corrosion resistance. It has the highest strength of the 6000 series alloys. Alloy 6082 is known as a structural alloy. In plate form, Aluminium alloy 6082 is the alloy most commonly used for machining. As a relatively new alloy, the higher strength of Aluminium alloy 6082 has seen it replace 6061 in many applications. The addition of a large amount of manganese controls the grain structure which in turn results in a stronger alloy.
Silicon content between 9,5 to 11,5% offers good castability and excellent die-filling capabilities. This is important when large parts are cast or when complicated die designs have to be filled. Since silicon expands during solidification, lower shrinkage behaviour and hot tearing tendencies are avoided compared to other alloys systems. The eutectic silicon is modified by strontium. This is very important for ductility because strontium additions change the silicon morphology from a blocky or lamellar type into a more coral like form. Strontium will enhance hydrogen pick-up in the melt requiring an efficient melt cleaning device such as impeller technique. This will keep hydrogen content low decreasing porosity and providing good weldability. 
Besides silicon, manganese and magnesium have the most important influence on resulting properties. Experiments were carried out to optimise the manganese content and to evaluate magnesium content to improve ductility. 
It was established in the literature, that manganese lowers ductility in an AlSiMg alloy when its content exceeds 0,2%. For this reason, manganese was not recommended as an addition to high-pressure die-casting alloys to substitute iron or as a combination with iron. To get a better understanding of the performance, a series of tests were carried out with different manganese content ranging from 0,04% to 1,2%.
Magnesium was added in the range of 0,003 up to 0,1%. The manganese content was kept at the optimum level of 0,6% and the strontium content of 120 ppm which provides a good modification of the eutectic silicon. A test sample with dimension of 220 mm x 60 mm x 3 mm was cast to determine mechanical properties. The test plate was cast in a single cavity die. Again, a 400 t die-casting machine was used with an adapted forced venting system. The melt was degassed by using spinning nozzle techniques and the quality was checked with the lowpressure test. Before degassing density index was observed to be between 3% and 5%. After treatment a density index was less than 2%. No dependency between magnesium content and resulting density indices could be observed.
The purpose of this study, gun body's product from 6082 alloy with forging method, we intend to produce gun's body with die casting method. For this purpose, we search to raw material for die casting method which is have suitable property like 6082 alloy. And with this kind of aluminum raw material we use die casting method and we produced gun's body with die casting.
With die casting method for gun's body, we aim that increase  production rate and reduce labor costs. Also, gun's body size and weight very suitable for die casting method.
During the formation of theses, firstly we choose suitable raw material and observe the mold design. And we aim sent to company smoothly.