چكيده به لاتين
Nowadays, in many engineering applications, it is not possible to use one type of material that satisfies all the desired properties. Therefore, alloys have received much attention. Titanium and aluminum alloys are used in various industries, including aerospace, due to their superior physical and mechanical properties. Mechanical joints are considered as the most central part assembly process in these industries. However, the drilling of these alloys has shown limitations such as high thrust force, poor heat dissipation, and severe holes at the drill exit. The current research was carried out with the aim of experimental evaluation of cooling methods in the efficiency of helical milling and drilling of titanium-aluminum alloys, and to compare different methods of creating holes, i.e. drilling and helical milling, as well as investigating different flood cooling methods, the minimum amount of fluid, Refrigeration and integration of these two in these alloys have been discussed. The effect of different drilling methods and machining parameters has been investigated throughout the workpiece. Different parameters can effectively affect the formation of holes in drilling and milling. By examining the effect of the shear speed parameter, the optimal method for drilling was identified, and by applying cooling methods and comparing them, the best method of drilling in two pieces of aluminum 7075 and titanium grade 2 connected together by examining and studying the data obtained from cylindrical tolerance analysis, diameter deviation, hole surface roughness, chip shape and machining tool wear were selected. Also, the chemical composition of aluminum and titanium alloy was determined using quantum analysis. In order to reduce the number of tests and evaluate the effect of important parameters on the drilling process, in the first step, the cutting speed was considered as a variable relative to the table advance. In one of the experiments, the drilling parameter was selected as a multiple and with a constant cutting speed. In this design, a total of 8 experiments were repeated twice. This was done in order to better investigate the conditions of drilling in two alloys with the same parameters so that the comparison with drilling with variable parameters is more concrete. The results showed that in the drilling process, due to the high forces and vibration, the drill tip will rise and go through a larger circular motion, and the production hole will be relatively conical. In the process of helical milling, due to the significant low forces, the rise of the tool will be much less, as a result, the taper of the hole will be significantly reduced. Therefore, helical milling of titanium and aluminum alloy at high speed creates holes with high quality and minimal roughness. By changing the cooling conditions, we find that in the lubrication conditions, the minimum value is the minimum value of hole roughness, cylindrical tolerance, diameter deviation and tool wear. As a result, this method is a suitable option for cooling the desired part due to its lower environmental impact, lower price and higher hole quality.
