Development of cast and heat treated 7075 alloy rifle receiver

Güngör, Ahmet Umur
Developing technology in the world makes products lighter and have higher strength values. That’s why, aluminum and titanium alloys start to be used instead of steel. It can be seen that 7075 aluminum alloy is one of the highest strength amongst the aluminum alloys. This alloy has a close tensile strength value to some steels, with help of the heat treatment applications and developing production technologies. Generally, industrial usage of 7075 alloy is machining of 7075 alloy extrusion slab into desired shape. However, it becomes costly and time wasting as making complicated and hollow products. Therefore, near net shape methods like thixoforming and squeeze casting are vital for these conditions. This work aimed to replace production method of rifle receiver part which is machined into a hollow structure from extruded T6 heat treated 7075 alloy slab which cause heavy raw material lost with casted and T6 heat treated preform which has close tensile properties and needs very little machining to turn into receiver part. In order to achieve this purpose, squeeze casting, thixoforming, sand casting, gravity die casting, SIMA and high pressure die casting experiments were conducted. In order to investigate mechanical properties of samples, tensile and hardness tests were performed. X-Ray Diffraction analysis (XRD) and Scanning Electron Microscopy analysis (SEM) were conducted to determine the intermetallics inside of samples after heat treatment. Moreover, average grain size of samples was obtained by optical microscopy technique. Newtonian thermal analysis method was used to compute solid fraction values with respect to temperature and time. Target mechanical values were determined as mechanical properties of extruded 7075-T6 alloy which are 150 HB hardness, 505 MPa yield strength and 11% elongation. Hardness target was reached after T6 heat treatment with squeeze casting method as 150 HB, die casting with vacuum support method as 160 HB and thixoforming method as 173 HB. Other methods could not reach the target hardness and has hardness values between 100 HB and 130 HB. 505 MPa yield strength target was achieved only by thixoforming method with 0.67 solid fraction as 526 MPa. Other close results were 429 MPa with squeeze casting method and 365 MPa with SIMA method. Elongation target was reached by semi-solid injection molding method as 11.5% but its other mechanical properties were poor. Elongation results of other methods were found to be between 4% and 5%.


Waste Generation in Primary and Secondary Aluminum Sector in Turkey
Küçük, Elif; Danacı, Dilara; Yetiş, Ülkü (null; 2017-06-21)
Aluminum is the most produced and used metal following steel in the world because of its combination of physical properties. Aluminum is produced in two ways; primary aluminum production and secondary aluminum production. The main objectives of this study are to find out waste generation in aluminum industry, to determine waste generation factors(WGFs)and to suggest best available techniquesfor the management of wastes from this activity. Fordetermination of waste g...
Development of high strength aluminum matrix composite backing plates for ballistic armor
Durmaz, Tayfun; Kalkanlı, Ali; Department of Metallurgical and Materials Engineering (2017)
Recently, aluminum and aluminum alloys have gained great importance in engineering applications by the help of technological developments. Today, it is possible to see aluminum alloys in very different sectors of industry because of their superior properties. Some of these important properties are high specific strength, lightness and ductility. In addition, it has low density, high corrosion resistance and high mechanical properties that make aluminum crucial in transportation, construction, packaging, hou...
Analysis of magnesium addition, hydrogen porosity and T6 heat treatment effects on mechanical and microstructural properties of pressure die cast 7075 aluminum alloy
Alat, Ece; Kalkanlı, Ali; Department of Metallurgical and Materials Engineering (2012)
Aluminum alloys are having more attention due to their high specific stiffness and processing advantages. 7075 aluminum alloy is a wrought composition aluminum alloy in the Al-Zn-Mg-Cu series. Due to the significant addition of these alloying elements, 7075 has higher strength compared to all other aluminum alloys and effective precipitation hardenability characteristic. On the other hand, aluminum alloys have some drawbacks, which hinder the widespread application of them. One of the most commonly encounte...
Severe plastic deformation of age hardenable aluminum alloys
Tan, Evren; Ögel, Bilgehan; Gür, Cemil Hakan; Department of Metallurgical and Materials Engineering (2012)
Industrial products of high-strength Al-alloys are currently manufactured by thermo-mechanical processes, which are only applicable in the integrated plants requiring high investment cost. Moreover, reduction of the average grain size not less than 10 μm and re-adjustment of process parameters for each alloy type is evaluated as disadvantage. Therefore, recently there have been many research studies for development of alternative manufacturing techniques for aluminum alloys. Research activities have shown t...
Thermo-mechanically coupled numerical and experimental study on 7075 aluminum forging process and dies
Özcan, Mehmet Cihat; Gökler, Mustafa İlhan; Department of Mechanical Engineering (2008)
Combination of high strength with light weight which is the prominent property of aluminum alloy forgings has led aluminum forgings used in rapidly expanding range of applications. In this study, to produce a particular 7075 aluminum alloy part, the forging process has been designed and analyzed. The forging process sequence has been designed by using Finite Volume Method. Then, the designed process has been analyzed by using Finite Element Method and the stress, strain and temperature distributions within ...
Citation Formats
A. U. Güngör, “Development of cast and heat treated 7075 alloy rifle receiver,” M.S. - Master of Science, Middle East Technical University, 2015.