1 / 42

Surface Technology Part 1 Introduction

Surface Technology Part 1 Introduction. Professor Kenneth W Miller Office A108 Phone 0841 9348 0324. Topics for Today. Course Syllabus Introductions My background What is your background What are your areas of interest Automobile Parts of Interest Materials of Interest

nishan
Télécharger la présentation

Surface Technology Part 1 Introduction

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Surface TechnologyPart 1Introduction Professor Kenneth W Miller Office A108 Phone 0841 9348 0324 Surface Technology

  2. Topics for Today • Course Syllabus • Introductions • My background • What is your background • What are your areas of interest • Automobile Parts of Interest • Materials of Interest • What is Not Covered • Fundamentals of Materials Science Surface Technology

  3. Automotive Parts of Interest • Body in White • Suspension Components • Brake Components • Steering Components • Space Frames • Accessories • Mirrors • Antenna Surface Technology

  4. Enemies List • Metal to metal contact • Sun • Water • Salt • Rocks • Grocery carts • Time Surface Technology

  5. Body and Frame Functions • Strength • Frame • A, B, and C Pillars • Suspension and Steering Components • Braking Components • Cosmetic • Body panels • hood Surface Technology

  6. Steel Carbon Steel HSLA Stainless Steel New Alloys Aluminum Magnesium Polymers Composites Automotive Materials of Interest Surface Technology

  7. What is Not Covered • Engine and engine components • Tires • Polymers will get limited coverage • underbody impact protection • body parts Surface Technology

  8. Summary • Body in White is the Primary Topic • Steel is the Primary Material • Aluminum is Becoming Significant • Magnesium is of Limited Interest • What are the factors in material selection? Surface Technology

  9. Material StructureAtomic Level • Patterns of Atoms • Unit Cells • Body-Centered Cubic (BCC) • Face-Centered Cubic (FCC) • Hexagonal Close Pack (HCP) Surface Technology

  10. Material Structure - FCC Surface Technology

  11. Material Structure -BCC Surface Technology

  12. Material Structure - HCP Surface Technology

  13. Energy and Packing • Non dense, random packing • Dense, regular packing Surface Technology 2

  14. Material Structure - APF • Atomic Packing Factor • APF = Volume of atoms / Volume of cell • APF = 0.74 for FCC • APF = 0.68 for BCC • APF = 0.74 for HCP Surface Technology

  15. Material StructureCoordination Number • Nearest neighbors and touching atoms • Coordination Number = 12 for FCC • Coordination Number = 8 for BCC • Coordination Number = 12 for HCP Surface Technology

  16. Material Structure - FCC Surface Technology

  17. Material Structure - BCC Surface Technology

  18. Material Structure - HCP Surface Technology

  19. Strength of Materials • Determined by bond strength • Limited by slip planes • Slip planes and dislocations • Split planes and inclusions • Atomic separation (distances) Surface Technology

  20. Crystalline Defects Surface Technology

  21. Bond Strength Surface Technology

  22. Energy and Packing • Non dense, random packing • Dense, regular packing Surface Technology 2

  23. Granular Structure • Pure metals are rarely used • Practical limits to crystalline structure • Can create anisotropy • Reflects heterogeneous composition • Caused and changed through • Forming operations such as casting • Working operations e.g. rolling, drawing • Heat treatment Surface Technology

  24. Granular Structure Polycrystalline lead ingot Magnified 7x Surface Technology

  25. Granular Structure • Size – effects strength • Size – effects toughness • Orientation – affects directional strength • Orientation at surface – corrosion opportunities • Can be seen through a small microscope • Crystalline structure requires special equipment Surface Technology

  26. Strain • Engineering Strain • True Strain Surface Technology

  27. Stress • Engineering Stress • True Stress Surface Technology

  28. Stress and Strain • These are point functions • >0 for tension, <0 for compression • Both are directional • Both depend on plane considered • Normal stress and strain • Shear stress and strain • Full stress or strain state is represented as a 3x3 matrix Surface Technology

  29. Stress and Strain Surface Technology

  30. Material Properties • Tensile strength • Yield strength • Toughness • Hardness • Fracture toughness • Modulus of Elasticity • Poisson’s Ratio Surface Technology

  31. Stress and Strain • Elastic Range – linear • σ = E · ε • E is the modulus of elasticity or Young’s Modulus • Full recovery, no permanent change • Plastic Range – non-linear • Varies with material • Work hardening • Necking • Permanent change to size and strength Surface Technology

  32. Modulus of Elasticity Surface Technology

  33. Modulus of Elasticity Surface Technology

  34. Yield Point Surface Technology

  35. Necking Surface Technology

  36. Stress Strain • Power law relationship • Typical for steel and aluminum • Assumes slow strain • Assumes uniform temperature Surface Technology

  37. Stress Strain Surface Technology

  38. Poisson’s Ratio • Pull it and it gets thinner • Squish and it gets thicker • Consider a tensile specimen pulled in z • Upper limit is 0.5 for no material volume change Surface Technology

  39. Material Properties Surface Technology

  40. Discussion - Surfaces • Appearance • Cover minor flaws • Hide difference materials • Protection from Corrosion • Protection from scratches or impacts • Increase / decrease friction • Improve scratch resistance (hardness) Surface Technology

  41. Manufacturing Considerations • Cost • Speed – timing for production • Downstream effects • Value to the consumer • Weight • Appearance • Safety Surface Technology

  42. Manufacturing Cost • Materials • Time • Equipment • Flexibility (changeover time and cost) • Labor • Waste disposal (toxic?) Surface Technology

More Related