GATING SYSTEM PPT
- 1. Seminar on “Gating System” JAGANNATH M.Tech(CIM) M.S.R.I.T 1MS16MCM08
- 2. Contents • Introduction • Elements of Gating System • Functions of gating system • Defects occurring due to improper design of gating system • Types of Gates • Pouring Time • Gating Ratio • Guidelines for Designing Gating System • Review of papers • Conclusion • References 2
- 3. Introduction • Mould is used for producing a casting. Molten metal is conveyed into the mold cavity by using Gating system. • In casting process, gating system plays an important role to produce a high quality casting. • A poorly designed gating system results in casting defects. • A gating system controls mould filling process. The main function of gating system is to lead molten metal from ladle to the casting cavity ensuring smooth, uniform and complete filling. 3
- 4. Elements of Gating System • Pouring Cup • Sprue • Sprue well • Cross-gate or Runner • Ingate or Gates 4
- 5. Pouring Cup It is the funnel-shaped opening, made at the top of the mold. The main purpose of the pouring basin is to direct the flow of molten metal from ladle to the sprue. Sprue It is a vertical passage connects the pouring basin to the runner or ingate. It is generally made tapered downward to avoid aspiration of air. The cross section of the sprue may be square, rectangular, or circular. Sprue well It is located at the base of the sprue. It arrests the free fall of molten metal through the sprue and turns it by a right angle towards the runner. Runner It is a long horizontal channel which carries molten metal and distribute it to the ingates .It will ensure proper supply of molten metal to the cavity so that proper filling of the cavity takes place. Gates These are small channels connecting the mould cavity and the runner.The gates used may vary in number depends on size of the casting. 5
- 6. Functions of gating system • A good gating system should help easy and complete filling of the mould cavity. • It should fill the mould cavity with molten metal with least amount of turbulance. • It should prevent mould erosion. • It should establish proper temperature gradient in the casting. • It should promote directional solidification. • It should regulate the rate of flow of metal into the mould cavity. 6
- 7. Defects occurring due to improper design of gating system • Oxidation of metal • Cold shuts • Mould erosion • Shrinkages • Porosity • Misruns • Penetration of liquid metal into mould walls. 7
- 8. Types of Gates • Depending upon the orientation of the parting plane. – Horizontal Gating System – Vertical Gating System • Depending upon the position of ingate(s), horizontal gating system. – Top Gating System – Bottom Gating System – Parting-line Gating System 8
- 9. 9
- 10. Pouring Time • Pouring rate is nothing but the time taken for filling the mould cavity by a known quantity of metal i.e., Pouring time can be used as an index to determine the pouring rate. • When molten metal is being poured into the mould at a very fast rate, mould erosion, rough surface, excessive shrinkage may takesplace. • When the pouring rate is very low, the complete filling of the mould is not assured and may result in excessive drop in the molten metal temperature. • This result in casting defects such as cold shut, misrun etc., • In order to avoid this, it is necessary to arrive at the correct rate of pouring of metal into the mould cavity. • The type of metal, size and shape of the casting decide the pouring rate. 10
- 11. Gating Ratio Gating ratio refers to the relation between area of the choke to total area of runner total area of Ingates. Mathematically, it can be written as Ac: Ar: Ag . The gating system completely controls the molten metal flow. Gating systems can be classified as Pressurised system and Unpressurised system. Gating ratio depends on the nature of the molten metal. • Pressurized system is used for reactive metals like magnesium alloy etc. Unpressurised gating system is used for normal metals such as brass, steel, aluminium alloy, etc. • A Gating ratio such as 1:2:1 or 1:0.75:0.5 refers to pressured system; whereas the gating ratio such as 1:2:2 or 1:3:3, 1:1:3, refers to unpressurised gating system. 11
- 12. • Pressurized system is referred to as “Gate control System”, since ingates controls the flow of metal. • Unpressurised system is referred to as “Choke Control System”, since the choke controls the flow of metal. • In the pressurized system high metal velocity occurs and results in turbulence. In the case of unpressurised system, turbulence is produced and streamline flow is induced. • Pressurized System Consumes less metal and yield is more. Unpressurised system consumes more metal and the yield will be slightly lowered. • In the case of pressurized system, the system will always be full of liquid metal . In the case of unpressurised system flow is not full. 12
- 13. Guidelines for Designing Gating System • The size of the sprue fixes the flow rate. The amount of molten metal that can be fed into the mold cavity in a given time period is limited by the size of the sprue. • The sprue should be located at certain distance from the gates so as to minimize velocity of molten metal at ingates. • Sprue should be tapered by approximately 5% minimum to avoid aspiration of the air and free fall of the metal. • Ingates should be located in thick regions. • Locate the gates so as to minimize the erosion of the sand mold by the metal stream. This may be achieved by orienting the gates in the direction of the natural flow paths. • Multiple gating is frequently desirable. This has the advantage of lower pouring temperatures, which improves the metallurgical structure of the casting. In addition, multiple gating helps to reduce the temperature gradients in the casting.13
- 14. Conclusion To reduce warpage proper gating system plays a major role. Optimized gating system improving casting quality and increasing casting yield. Optimum gating position leads to sound casting. Proper gating framework are essential to secure quality of casting. 14
- 15. References • Review on Casting Defect: Warpage Surabhi Pareek1 V.S.Khangar2 , 1Student M. Tech (CAD/CAM) 2Assistant Professor 1, 2Department of Mechanical Engineering 1, 2GHRCE an Autonomus Institute, Nagpur- 420016, India • Gating system design for warpage reduction 1Surabhi Pareek, 2V.S.Khangar 1Student M.Tech CAD/CAM, GHRCE, Nagpur- 420016, India 2Assistant professor, GHRCE, Nagpur- 420016, India • Numerical optimization of gating system parameters for a magnesium alloy casting with multiple performance characteristics Zhizhong Suna,∗, Henry Hua, Xiang Chenb a Department of Mechanical, Automotive & Materials Engineering, University of Windsor; Windsor, Ontario, Canada N9B 3P4 ,b Department of Electrical & Computer Engineering, University of Windsor; Windsor, Ontario, Canada N9B 3P4hetiya 15
- 16. • A review on optimization of gating system in metal casting sandeep singh1, lakhwinder pal singh2 & gurudutt sahni3 1 Research Scholar, Department of Industrial and Production Engineering, National Institute of Technology Jalandhar, Punjab, India 2Assistant Professor, Department of Industrial and Production Engineering, National Institute of Technology Jalandhar, Punjab, India 3 DGM &HOD, CE, PE, Design, Drawing and Development, Leader Valves Ltd, Jalandhar, Punjab, India • A Review on Optimization of Gating System for Reducing Defect Swapnil A. Ambekar1 Dr. S. B. Jaju2 1 M.Tech Student, Department of Mechanical Engineering, GHRCE , Nagpur 2 Dean, R&D Department, Department of Mechanical Engineering, GHRCE , Nagpur. • Design and Analysis of Gating and Risering System for Casting of Ball Valves ,P. G. Panchal, S. J. Joshi and N. D. G 16
- 17. THANK YOU 17
- 18. S.No Title Author Published Workdone Remarks 1 Casting Defect: Warpage Surabhi Pareek1 V.S.Khangar2 IJSRD - Vol. 3, Issue 02, 2015 | ISSN (online): 2321-0613 Casting produced by foundry with distortion as a major defect was analyzed and identified solution for its cause. To reduce warpage proper gating system plays a major role with the help of casting simulation technology to reduce the lead time and improve productivity 2 Numerical optimization of gating system parameters for a magnesium alloy casting with multiple performance characteristics Zhizhong Sun, Henry Hu, Xiang Chen journal of materials processing technology 1 9 9 ( 2 0 0 8 ) 256– 264. Used an optimization method for design of a casting based on the Taguchi method for multiple performance characteristics. The simulation results indicated that gating system parameters significantly affect the quality of the magnesium casting. 3 Gating system design for warpage reduction Surabhi Pareek, 2V.S.Khangar 1Student M.Tech CAD/CAM, GHRCE, Nagpur- 420016, India ISSN(O):2393-9877, ISSN(P): 2394-2444, Volume 2,Issue 4, April- 2015 In this work AUTOCAST software has been used for designing proper gating system . Optimum riser position leads to sound casting. A proper gating system design with the help of casting simulation software helps to eliminate defects at large. Review of papers 18
- 19. 19