EFFECT OF DIE DESIGN ON MECHANICAL PROPERTIES OF HOT PRESSED 6063

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "EFFECT OF DIE DESIGN ON MECHANICAL PROPERTIES OF HOT PRESSED 6063"

Transcription

1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 8, Issue 3, March 2017, pp Article ID: IJMET_08_03_047 Available online at aeme.com/ijmet/issues.asp?jtype=ijmet&vtyp pe=8&itype=3 ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed EFFECT OF DIE DESIGN ON MECHANICAL PROPERTIES OF HOT PRESSED 6063 ALLOY S.Dhivakaran PG Scholar, Department of Mechanical Engineering, PRIST University, Thanjavur , TN, India M.Sudhahar Assistant Professor, Department of Mechanical Engineering, PRIST University, Thanjavur , TN, India P.Vijayakumar Associate Professor, Department of Mechanical Engineering, PRIST University, Thanjavur , TN, India ABSTRACT In this work, the simple and economic press die setup was fabricated and the effect of die on mechanical properties of 6063 aluminium alloy is taken into account. The specimen served into the die was heat treated at 570 C to control the intermetallics by dissolving them into matrix alloy with thermo mechanical process. The mechanical properties were analyzed in all the samples where they are in raw, annealed and hot pressed conditions. The higher tensile strength of 190 MPa has obtained at pressed condition while compared to anneal one. The hardness of die-pressedd alloy is higher than the annealed condition. Keywords: Aluminium, Tensile strength, hot Press, Die mould. Cite this Article: S.Dhivakaran,M.Sudhahar and P.Vijayakumar, Effect of Die Design on Mechanical Propertieses of Hot Pressed 6063 Alloy. International Journal of Mechanical Engineering and Technology, 8(3), 2017, pp IType=3 1. INTRODUCTION The aluminium alloy still used very widely and proving its vital role in different applications like commercial vehicles, rail cars, marine hulls and superstructures, military vehicles and high pressure gas cylinders due to its good strength to weight ratio. The processing routs are very important factors in the production of aluminium [8]. By which the properties and cost can be varied. Generally the variety of secondary process are followed in production of aluminium like extrusion, rolling etc., to control the pores developed during casting by which

2 S.Dhivakaran, M.Sudhahar and P.Vijayakumar the mechanical properties are improved apart from the alloy compositions. While Die-casting more expenses in experimental setups which influence the rise in cost. Properties are varied due to amount of compositional elements like magnesium, copper, silicon, and chromium and other and properties can be enhanced by introducing manufacturing methodology and heat treatment. During cooling the aluminium alloys, the gradual solidification (slow cooling) can allows the microsegregations of alloying elements which is very hard and rapid cooling or heat treatment can control the formation of micro segregation [5]. 2. MATERIALS AND METHODS 2.1. Equipment Design In this work the economic press die is prepared as shown in figure.1 using high carbon thick steel plates and the die fabricated by high strength welding rod. The Die which has provision to eject the material out and the entire setup is held under UTM (Universal Testing Machine) with 400 kn Capacity. Moreover the die design is especially made for preparing 25 X 30 X 150 mm specimen size. And the material used for die press is an aluminium alloy in wrought form Die design The die design is expected to make simple and in economic mode. But the materials should have the ability to resist the maximum stress developed during hot pressing. Since the materials selection is strongly considered as high strength and temperature resistance. And moreover the die is especially made for pressing aluminium and alloys. For that the high carbon material has very well in properties to resist the stress developed while punching. The die was designed in rectangular shape which is capable to punched out the rectangular bars of 30 X 30 X 150 mm and sizes of the bars entered into the die will vary depends upon the properties of the alloy used. Figure1 Die dimensions

3 Effect of Die Design on Mechanical Properties of Hot Pressed 6063 Alloy The unit containing three part assemblies like die part (1), punch tool (2) and loose piece part to eject the bars out with the two ejecting plungers and supporting blocks as shown in figure. 1 and more over the entire construction of the die made with high strength weld by industrial arc welding. The stresses on the elemental volume are 1) P= forging pressure ii) σ x = longitudinal stress due to lateral flow of the metal iii) τ= shear stress due to friction between work and die surfaces. The following expression is considered when sliding friction at the contact surface between work and die, The following expression is considered when sticking friction at interfaces, (1) the work and die By equation (2), sticking friction considered, (2) Height (h) =25 mm, 2a = 150 mm width (b)= 30 mm (constant) Punch pressure = P av x length x width Figure 2 Tensile specimen

4 3. EXPERIMENTAL DETAILS S.Dhivakaran, M.Sudhahar and P.Vijayakumar The aluminium alloy of 25 X 25 X 140 mm size pieces are heated to 450º ºC with heat rate of 1ºC/ 5 sec and held it for one hour in the muffle furnace and then served it to the 400ºC preheated press die. The compressive load applied on punch is measured as 150 kn. The solutionizing heat treatment which tempers the alloy to be unstable [6] so the hardness can be increased for increased temperature [4] and moreover higher the solutionizing temperature which larger the distribution of elements who are not dissolved in casting due to diffusion kinetics at elevated temperatures and especially by soaking time, that means increasing the soaking period which increase homogeneity in solid solution. Hencee he solutionizing temperature was increased to 570ºC and the soaking period is fixed as 90 minutes and hot pressed specimens are measured in length, breath and thickness and compared with raw specimens the tensile test was conducted for no of non-heat treated and heat treated alloy specimens on Universal Testing machine and load and strain in mm was measured. The tensile samples were machined on lathe with ASTM standards as shown in figure.2. The hardness of all the heat treated and un-heat treated specimens were measured using Rockwell hardness tester, in this work and B scale is selected for aluminium alloy material and load supplied to aluminium alloy is 200 kn as per standard. Figure 3 Pressing and Tensile testing Table 1 Chemical Composition Of 6063 Aluminum Alloy Elements Mg Si Fe Cr Cu Ti Mn Zn Al max Bal

5 Effect of Die Design on Mechanical Properties of Hot Pressed 6063 Alloy 4. RESULT AND DISCUSSION Figure 4 Tensile test pieses and cut fracture surfaces In this work the raw 6063 aluminium alloy was received in T6 condition. So initially the alloy is heat treated to 450 C and soaked for 1 hr which gives the total deformation on the rectangular bar as 5-6 mm due to hot pressing on UTM under 150 kn hydraulic loads. The compressive strain is increased for increased solutionizing temperature and increased soaking time. That means the alloy is then solutionized at 570 C for 90 minutes. For this increased temperature the total deformation of the solid bar also increased to 16 mmm of the alloy while hot pressing under increased load as 300 kn on UTM. The tensile strength of the 450 C heat treated alloy is less than the as received (extruded) one due to the precipitation of non coherent particles of Mg 2 Si formed on the grain boundary [3].Moreover the possibility of loss in strength has observed by the development of pores by solution annealing. By this low temperature heat treatment, recrystallization could not be obtained due to fine intermetallic distribution in the matrix alloy. And for higher temperature of 570 C, fine grains are obtained and moreover the reduction of intermetallics and small particle coarsening is possible in α matrix. The grain coarsening could not be observed for shorter soaking time at higher temperature [7]. The grain refinement which causes the improvement in mechanical properties. However the retention of more amounts of solute elements in the matrix while shorter heat treatment. It is the reason for that the increase in strength was observed from the hot pressed alloy over heat treated alloy. The figure 5 shows the tensile properties of a 6063 aluminium alloy in different conditions. The higher strength of 190 MPa is achieved almost closer to the strength tested as 204 MPa of extruded and tempered alloy received. it is notable one in this work, that is the almost equal strength has achieved by the effect of economic methodology provided as punch and die design prepared as shown in figure.1 The figure 6 depicts the hardness properties of a 6063 aluminiumm alloy in different conditions. The hardness of the alloy is initially decreased due to only of annealing temperature but higher the temperature and higher the pressure which increases the hardness

6 S.Dhivakaran, M.Sudhahar and P.Vijayakumar Figure 5 Tensile strength of 6063 aluminium alloy in different conditions 5. CONCLUSION Figure 6 Hardness of 6063 aluminium alloy in different conditions The simple and economic press die setup was fabricated and the effect of die on mechanical properties of 6063 aluminium alloy was analyzed in this work. 1. The tensile properties were improved by die pressing the solution annealed samples at higher loads. 2. Higher the temperature and larger the dissolution of solute into the matrix alloy. However the grain coarsening is controlled or avoided and distribution fine grains throughout the matrix alloy by introducing mechanical pressure by die prepared. Since both the tensile and hardness properties are improved. 3. The hardness magnitude which confirms the dissolution of solute particles in to the matrix uniformly by the combinationn of solution annealing treatment and influence of die fabricated. REFERENCES [1] Effect of punch diameters on shear extrusion of 6063 Aluminium alloy, Mutiu F Erinnosho, Saheed O Ojo, Joseph S Ajiboye, Esther T Akimlabi, World congress on engineering 2015 vol II

7 Effect of Die Design on Mechanical Properties of Hot Pressed 6063 Alloy [2] Effect of Processing Steps on the Mechanical Properties and Surface Appearance of 6063 Aluminium Extruded Products, Juan Asensio-Lozano, Beatriz Suárez-Peña and George F. Vander Voort, Materials 2014, 7, [3] Improvement on the strength of 6063 aluminum alloy by means of solution heat treatment, D.E.Esezobor, S. O. Adeosun, Materials Science and Technology (MS&T) 2006 [4] Influence of heat treatment on the mechanical properties of AA 6066 alloy, evren TAN and Bilgehan OGEL, Turkish J.Eng. Env.Sci. (53-60),2007. [5] Effect of heat treatment on some mechanical properties of 7075 aluminium alloy, Adeyemi Dayo Isadare, Bolaji Aremo, Mosobalaje Oyebamiji Adeoye, Oluyemi John Olawale, Moshood Dehinde Shittu, Materials Research,2013; 16(1); [6] Introduction to Physical metallurgy, Sidney H avner, Tata Mcgraw-Hill edition. [7] Enhancement of aluminium alloy forgins through rapid billet heating, Robert Kervick, Craig A. Blue and Puja B. Kadolkar, Teiichi Ando, Hui Lu, and Kozo Nakazawa, Howard Mayer, George Mochnal, ORNL/TM-2006/30. [8] Alloy Designation, Processing, and Use of AA6XXX Series Aluminium Alloys, Prantik Mukhopadhyay,International Scholarly Research Network ISRN Metallurgy Volume 2012, 15 pages. [9] Syambabu Nutalapati, D. Azad and G. Swami Naidu,(2016), Effect of Welding Current on Welding Speed and Ultimate Tensile Strength (UTS) of Mild Steel, International Journal of Mechanical Engineering and Technology, 7(5), 2016, pp [10] Maridurai T,Shashank Rai, Shivam Sharma and Palanisamy P, (2012), Analysis of Tensile Strength and Fracture Toughness Using Root Pass of Tig Welding and Subsequent Passes of Smaw And Saw Of P91 Material For Boiler Application, International Journal of Mechanical Engineering and Technology (IJMET), 3(2), pp [11] P. Govindarao, P. Srinivasarao, A. Gopalakrishna and C V sriram, Improvement of Tensile Strength of Butt Welded Joints Prepared By Vibratory Welding Process, International Journal of Mechanical Engineering and Technology, 4(4), pp