Abstract: Grinding process is necessary final process of making cylindrical parts with less than Ra 0.4 surface roughness. Generally we cannot obtain good surface quality without grinding process. As the experience of the authors, using CBN (Cubic Boron Nitride) insert to turning cylindrical parts could be obtained Ra 0.438 surface roughness. The surface roughness result is similar to ground parts. This result becomes the main focus of the study. Authors study to find out factors affecting CBN performance in turning with CBN to obtain less than Ra 0.4 surface roughness. According to the study, it was found that tool contact area allied to surface roughness. The experiment is turning S45C medium carbon steel under the following condition: Cutting speed is 300 m./min, Feed is 0.05 mm./rev and depth of cut is 0.1 mm. Experiment under the same condition in different contact area. Modify contact area of CBN insert to be 5,10,15,20 and 25 mm. and testing in order. CBN insert standard type contact area is 0 mm. Compare test results of modified CBN inserts with standard type result. The results of experiments were as follows: 1) Turning steel with CBN contact area 10 mm. was obtained Ra 0.456 surface roughness, 2) Turning steel with CBN contact area 15 mm. was obtained Ra 0.293 surface roughness, Thus less than Ra 0.4 surface roughness.
Abstract: This Paper presents the study on the weldability of two similar and two different metallic materials. The weldability of the similar metallic materials considered in the study were aluminum alloy pipes of grade AA6063. As for the weldability of two different metallic materials were aluminum alloy of grade AA6061 to low carbon steel of grade A36, dupl stainless steel of grade 2205 to low carbon steel of grade A36 and grey cast iron of grade A48 class 35 to low carbon steel BS 449 of grade 250. The differing methods of welding or joining processes are discussed herein including those of stir welding and hot pressed diffusion bonding of the similar and dissimilar metallic materials respectively as mentioned above. The weldability of between the two materials are investigated including the physical appearance of the joints and the strength integrity of those so far achieved at this stage. The paper also presented the results on the weldability of the similar and different metallic materials, recommendation for further in-depth study in pursuit for improved technologies on the subject matters and highlight the prospects of metallic materials welding or bonding or joining to fulfill the demands for different applications.
Abstract: This article represents the results of studies of the drawing thin wire from the alloy Pd-5Ni process. The studies used the software developed by the authors using the methods of calculating the drawing process and the computer model implemented in the DEFORM 3D software package. By way of calculation, a drawing route was determined, including 14 transitions, and the efforts of deforming the metal were found when producing wire with a diameter of 0.075. For this mode of deformation processing using the DEFORM 3D software package, we simulated the drawing process and established the temperature and stress distribution over the volume of the workpiece. The simulation results confirmed that the calculated safety factor for drawing is in the range of 2.85-3.43, which ensures a stable process of deformation of the metal without breaks and, as a consequence, an increase in productivity and yield of the suitable metal. Experimental studies have confirmed the adequacy of the developed model, so it can be used to analyze the process of drawing wire from other precious metal alloys. The results of the research are recommended to improve the production technology of thin wire from the alloy Pd-5Ni for the manufacture of catalytic gripping grids.
Abstract: This article presents the results of the study of the joint effect of the processing conditions of the new composition of the Al-Zr system alloy by combined casting and rolling-extruding and two-stage annealing on the structure and properties of round bars used in the manufacture of heat-resistant wires. The research show patterns of changes in the properties, the specific electrical resistance of the bars, depending on different conditions of deformation and heat treatment of aluminum alloy with a content of 0.3% zirconium and 0.2% iron. The results of micro-X-ray spectral analysis and the granular structure of the samples before and after two-stage annealing confirming the stability of the structure after heating and preserving the strength of semi-finished products. Presented parameters of combined casting and rolling-extruding and two-stage annealing for the manufacture of rods from the studied alloy make it possible obtaining good combination of mechanical properties and electrical conductivity.
Abstract: Article shows the results of studies of the process of combined rolling-extruding of an alloy of the Al-Mg system (AlMg6) under various temperature-speed and deformation conditions. Calculations shows that with increasing metal temperature at the entrance to the deformation center, the values of the forces on the rolls and the die decrease, the increase in drawing leads to an increase in the values of forces on both the rolls and the die, and an increase in the deformation rate leads to hardening of the metal and increasing energy parameters of the process of combined machining. However, the maximum extruding force on the combined machining units is 5-10 times lower than the efforts to obtain the same press products on hydraulic presses. A computer model of the combined machining process created with the help of the DEFORM 3D complex, the analysis of the metal flow is made, the temperature distribution of the metal over the section of the workpiece invstigated when producing round bars of different diameters. Shaping of the metal corresponds to the data of experimental and theoretical studies, while the deformation center has a characteristic appearance, including the gripping zones of the workpiece and its rolling, repressing and extrusion. The peculiarity for this alloy is that with a drawing ratio of μ = 3.7 and a strain rate of ξ = 0.78 s-1, the steady extruding process takes place without completely filling the deformation zone from the side of the roll with a protrusion. An increase in drawing ratio or strain rate leads to a decrease in the contactless zone or to its absence. The change in metal temperature also depends on the presence of a contactless zone, which contributes to an increase in heat transfer from the billet to the rolls. The results of the research were used to develop the technology for the production of welding wire from Al-Mg system alloys.
Abstract: The cross section of a thin rod cast by a single-wheel caster, for which the wheel cross section is an inverted trapezoidal groove, is concave. To make the cross section convex, an inner side-dam plate is proposed. A single-wheel caster with a flat wheel (without a groove) and rotating side-dam plates is also proposed. 5182 aluminum alloy rods with a convex or rectangular cross section can be cast. The area of the rod is smaller than 150 mm2. The diameter of the converted circle area is 15 mm.
Abstract: A small projection with a height and width of about 40 and 50 µm, respectively, was formed on a twin-roll-cast A356 aluminum alloy sheet by cold rolling at a rolling speed of 0.5 m/min. This projection was then used as a die to form a groove with a depth and width of about 40 and 50 µm, respectively, on a polyethylene terephthalate plate by pressing.
Abstract: The casting of a 600 mm-wide 5182 aluminum alloy strip was attempted using a single-roll caster equipped with a scraper. This caster could cast a strip at speeds ranging from 10 to 40 m/min. These casting speeds are much higher than that of a conventional twin-roll caster. The scraper load suitable for scribing the wide strip was investigated. The strip could be scribed at full width by the scraper. The mechanical properties of the strip were investigated using a tension test and a cup test. The tensile stress was 320 MPa and the elongation was 30%. When deep drawing was conducted, no striped pattern, which occurs via segregation, appeared when both surfaces were facing outside.
Abstract: This study shows that the latent heat of the aluminum alloy in an overlay strip is the key factor affecting the bonding quality of clad strips fabricated by a vertical-type tandem twin-roll caster. Three-layer clad strips, for which the base strip was 3003 aluminum alloy and the overlay strip was Al-1%Si, Al-2%Si, Al-11%Si (4045), Al-2%Mg, and Al-4.5%Mg (5182), respectively, were cast. The 4045 overlay strip bonded to the base strip. However, overlay strips made of the other alloys did not bond to the base strip. The latent heat of Si is much higher than that of Al, which in turn is higher than that of Mg. Therefore, the latent heat of the 4045 alloy was higher than that of the other alloys. The high latent heat of the 4045 alloy allowed it to heat the base strip to a temperature at which bonding was possible.