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FEA Simulation

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Kumar Katturaja
Kumar Katturaja

The document discusses a finite element simulation of laser shock peening on nickel chrome and cobalt chrome alloys for dental applications. Nickel chrome and cobalt chrome were selected as potential materials due to their biocompatibility, strength, and durability. Finite element analysis was conducted to compare the mechanical properties and strains of the materials with and without laser shock peening treatment. The results showed that cobalt chrome exhibited lower maximum strains than nickel chrome, indicating it is better suited for dental applications. Laser shock peening was found to improve the fatigue strength and compressive stresses of the materials.

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FINITE ELEMENT SIMULATION OF ND:YAG LASER SHOCKPEENED NICKEL CHROME, COBALT CHROME BASE METAL ALLOY FOR DENTAL APPLICATION ILAVARASAN S 2010118017 KARTHIKEYAN S 2010118024 KUMAR K 2010118026 SARATH RAJA G 2010118040 Project Guide Dr. K Shanmuga Sundaram Associate Professor Department of Mechanical Engineering College of Engineering, Guindy Anna University, Chennai-25
Introduction The main objective of this project is to give a solution to the material selection for the dental implants or any other dental treatments. Dental Implants are become necessary now a days. Because, • 69% of adults at an age of 35 to 44, lost at least one of their permanent teeth by accident, gum disease or failed root canal. • 26% of adults at an age of 74, have lost all their permanent teeth.
Objective Selecting the suitable material, laser for the dental application and comparing the changes in the mechanical properties after doing shock peening operation  Hardness  Wear resistance  Yield strength  Ultimate strength  Modulus of Elasticity The experimental results and the theoretical results (simulation) are compared and studied
Material Selection Selection of Materials are based on the following things, • Bio compatibility • Color • Life • Durability • Easy for shaping • Aesthetics • Physical properties • Low thermal conductivity and expansion • Resistance to wear and abrasion • Resistance to chemical erosion • Flexibility to adopt to a shape • Strength to withstand the Mastication force
Material Selection Disadvantages • Poor Strength • High cost • Low Wear resistance • Less aesthetics • Takes longer time to make • Difficult to adjust • Dull in tooth color • May irritate the sensitive teeth (conducts cold) • High cost • Galvanic Shock • More brittle • Less life • Chance for future cavities • More time to place o Gold Alloy o Porcelain o Plastic + Fine Glass o Titanium o Cobalt Chromium o Nickel Chrome
Suitable Materials CHEMICAL COMPOSITION :: Ni-Cr CHEMICAL COMPOSITION :: Co-Cr ELEMENT PROPOSITION NICKEL 65.2 % CHROME 22.5 % MOLYBDENUM 9.5 % OTHERS (Fe, Si, Mn, Nb) 2.8 % ELEMENT PROPOSITION COBALT 61 % CHROMIUM 26 % MOLYBDENUM 6 % TUNGSTEN 5 % OTHERS (Si, Fe, Ce) 2 %
Laser Shock Peening  Innovative surface enhancement process for increasing resistance of the components.  This process creates compressive stress, four to five times deeper than conventional shot peening process.  This compressive surface stresses inhibit the initiation and propagation of fatigue cracks.  The peening drives a high amplitude shock wave into a material surface using high energy pulsed laser.  Hence the purpose of this study is to compare mechanical properties with microstructure of Nd- YAG laser treated and non-treated on Ni-Cr and Co-Cr
Nd: YAG Laser Shock peening • 0.4 mm to 1 mm • Low cost and easily available • produce continuous laser at room temperature • portable systems
Parameter Constant Spot Diameter 1.2 mm Pulse Duration 10 ms Depth of Penetration 0.48 to 0.73 mm Argon Shielding 45 0 Peening Speed 160 mm/s No of Scan per Second 4 Variables Pulse Energy Density 450 , 340 , 430 J/cm2 Pulse Frequency 1.1, 0.5, 2.5 kHz Tensile Specimen using Pro/E
Finite Element Analysis  Structural – Static Analysis  Solid 185  Element Size 0.0001 (Fine Mesh) Meshed view of Specimen
Displacement Vector Sum X Component Displacement Y Component Displacement Z Component Displacement
1st Principal Stress Von Mises Stress XY Shear Stress Z Component Stress
1st principal Strain Von Mises Strain Z Component Strain Elastic Strain Intensity
Improved Mechanical Properties Vector Plot of Displacement Vector Plot of Elastic Strain
Result The Strain value of the Co-Cr Alloy got the smallest value than the Ni-Cr Alloy. So the less strain value material is opted for Dental applications. Obviously Co-Cr alloy is better than Ni-Cr alloy. Maximum Strain Value of Ni-Cr alloy : 657 Maximum Strain Value of Co-Cr alloy : 553
Result Since the Co-Cr alloy is suitable for dental applications, the Laser Parameter can be identified. Pulse Energy Density value at max. strain value is 360×104J/m2 Pulse Energy Density value at min. strain value is 420×104 J/m2 So the least strain value is occurred during the Pulse Energy Density value of 420 ×104 J/m2
Conclusion Laser Shock Peening process is a trendsetter now a days in the medical field. It’s low cost and accurate operations make it popular. So that it gives an exact solution for all kind of age group who are all came with a dental problem. Nickel Chromium and Cobalt Chromium are some important materials in dental implants. These materials can be used in dental applications without doing shock peening process. But it cannot withstand for a longer period. LSP improves the fatigue strength and compressive stress of the material. The aesthetics of Co-Cr is little lower than Ni-Cr. Otherwise Co-Cr is the strongest material and can be shaped into any molar shape.
REFERENCES [1] O Brian WJ. 2002 Dental Materials and their selection. Chicago IL. Quintessence Publishing Co., Inc.; 2002.p.372-377 [2] Ding K, Ye L. Laser Shock peening performance and process simulation. Cambridge: Woodhead Publishing; 2006 [3] Ballard P. Residual Stresses induced by rapid impact – Application for laser shocking. Ecolo Polytechnique, April 1991 [4] Philips and Anusavic. Science of Dental Materials

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FEA Simulation

  • 1. FINITE ELEMENT SIMULATION OF ND:YAG LASER SHOCKPEENED NICKEL CHROME, COBALT CHROME BASE METAL ALLOY FOR DENTAL APPLICATION ILAVARASAN S 2010118017 KARTHIKEYAN S 2010118024 KUMAR K 2010118026 SARATH RAJA G 2010118040 Project Guide Dr. K Shanmuga Sundaram Associate Professor Department of Mechanical Engineering College of Engineering, Guindy Anna University, Chennai-25
  • 2. Introduction The main objective of this project is to give a solution to the material selection for the dental implants or any other dental treatments. Dental Implants are become necessary now a days. Because, • 69% of adults at an age of 35 to 44, lost at least one of their permanent teeth by accident, gum disease or failed root canal. • 26% of adults at an age of 74, have lost all their permanent teeth.
  • 3. Objective Selecting the suitable material, laser for the dental application and comparing the changes in the mechanical properties after doing shock peening operation  Hardness  Wear resistance  Yield strength  Ultimate strength  Modulus of Elasticity The experimental results and the theoretical results (simulation) are compared and studied
  • 4. Material Selection Selection of Materials are based on the following things, • Bio compatibility • Color • Life • Durability • Easy for shaping • Aesthetics • Physical properties • Low thermal conductivity and expansion • Resistance to wear and abrasion • Resistance to chemical erosion • Flexibility to adopt to a shape • Strength to withstand the Mastication force
  • 5. Material Selection Disadvantages • Poor Strength • High cost • Low Wear resistance • Less aesthetics • Takes longer time to make • Difficult to adjust • Dull in tooth color • May irritate the sensitive teeth (conducts cold) • High cost • Galvanic Shock • More brittle • Less life • Chance for future cavities • More time to place o Gold Alloy o Porcelain o Plastic + Fine Glass o Titanium o Cobalt Chromium o Nickel Chrome
  • 6. Suitable Materials CHEMICAL COMPOSITION :: Ni-Cr CHEMICAL COMPOSITION :: Co-Cr ELEMENT PROPOSITION NICKEL 65.2 % CHROME 22.5 % MOLYBDENUM 9.5 % OTHERS (Fe, Si, Mn, Nb) 2.8 % ELEMENT PROPOSITION COBALT 61 % CHROMIUM 26 % MOLYBDENUM 6 % TUNGSTEN 5 % OTHERS (Si, Fe, Ce) 2 %
  • 7. Laser Shock Peening  Innovative surface enhancement process for increasing resistance of the components.  This process creates compressive stress, four to five times deeper than conventional shot peening process.  This compressive surface stresses inhibit the initiation and propagation of fatigue cracks.  The peening drives a high amplitude shock wave into a material surface using high energy pulsed laser.  Hence the purpose of this study is to compare mechanical properties with microstructure of Nd- YAG laser treated and non-treated on Ni-Cr and Co-Cr
  • 8. Nd: YAG Laser Shock peening • 0.4 mm to 1 mm • Low cost and easily available • produce continuous laser at room temperature • portable systems
  • 9. Parameter Constant Spot Diameter 1.2 mm Pulse Duration 10 ms Depth of Penetration 0.48 to 0.73 mm Argon Shielding 45 0 Peening Speed 160 mm/s No of Scan per Second 4 Variables Pulse Energy Density 450 , 340 , 430 J/cm2 Pulse Frequency 1.1, 0.5, 2.5 kHz Tensile Specimen using Pro/E
  • 10. Finite Element Analysis  Structural – Static Analysis  Solid 185  Element Size 0.0001 (Fine Mesh) Meshed view of Specimen
  • 11. Displacement Vector Sum X Component Displacement Y Component Displacement Z Component Displacement
  • 12. 1st Principal Stress Von Mises Stress XY Shear Stress Z Component Stress
  • 13. 1st principal Strain Von Mises Strain Z Component Strain Elastic Strain Intensity
  • 14. Improved Mechanical Properties Vector Plot of Displacement Vector Plot of Elastic Strain
  • 15. Result The Strain value of the Co-Cr Alloy got the smallest value than the Ni-Cr Alloy. So the less strain value material is opted for Dental applications. Obviously Co-Cr alloy is better than Ni-Cr alloy. Maximum Strain Value of Ni-Cr alloy : 657 Maximum Strain Value of Co-Cr alloy : 553
  • 16. Result Since the Co-Cr alloy is suitable for dental applications, the Laser Parameter can be identified. Pulse Energy Density value at max. strain value is 360×104J/m2 Pulse Energy Density value at min. strain value is 420×104 J/m2 So the least strain value is occurred during the Pulse Energy Density value of 420 ×104 J/m2
  • 17. Conclusion Laser Shock Peening process is a trendsetter now a days in the medical field. It’s low cost and accurate operations make it popular. So that it gives an exact solution for all kind of age group who are all came with a dental problem. Nickel Chromium and Cobalt Chromium are some important materials in dental implants. These materials can be used in dental applications without doing shock peening process. But it cannot withstand for a longer period. LSP improves the fatigue strength and compressive stress of the material. The aesthetics of Co-Cr is little lower than Ni-Cr. Otherwise Co-Cr is the strongest material and can be shaped into any molar shape.
  • 18. REFERENCES [1] O Brian WJ. 2002 Dental Materials and their selection. Chicago IL. Quintessence Publishing Co., Inc.; 2002.p.372-377 [2] Ding K, Ye L. Laser Shock peening performance and process simulation. Cambridge: Woodhead Publishing; 2006 [3] Ballard P. Residual Stresses induced by rapid impact – Application for laser shocking. Ecolo Polytechnique, April 1991 [4] Philips and Anusavic. Science of Dental Materials