1 / 17

Properties of Materials

Properties of Materials. Prepared by: Dental Materials Department Yenepoya Dental College, Yenepoya University, Mangalore. Why /How do materials fail?. Types of Material Failure. Deformation failure

coopert
Download Presentation

Properties of Materials

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. Properties of Materials Prepared by: Dental Materials Department Yenepoya Dental College, Yenepoya University, Mangalore.

  2. Why/How do materials fail?

  3. Types of Material Failure • Deformation failure • A change in shape or size of a component that is sufficient for its function to be lost or impaired. • Fracture • Cracking to the extent that a component is separated into two or more pieces. • Corrosion • The loss of material due to chemical action.

  4. Wear • Surface removal due to abrasion or sticking between solid surfaces that touch • Erosion • The wear caused by a fluid (gas or liquid)

  5. Material Properties • Chemical Properties • Physical Properties • Mechanical Properties

  6. Chemical Properties • Material characteristics that relate to the structure of a material and its formation from the elements. • Cannot be determined by visual observation.

  7. Composition • Determined by analytical chemistry techniques  percentage of each component Avoid selecting materials by trade names. Try to obtain and understand the composition of materials used in design.

  8. Microstructure • Grain size • Inclusion • Phases • Methods to obtain: • Metallography, Ceramography  Chemical etching • Microtomy (polymer)Polarized light transmitting

  9. Crystal Structure • Method to obtain • X-ray diffraction • Will indicate melting characteristics, mechanical properties,… Corrosion Resistance • Degradation of a material by reaction with its environment

  10. Physical Properties • Characteristics of materials that pertain to the interaction of these materials with various forms of energy and with other forms of matter. • Can usually be measured without destroying or changing the material. • Color, density,…

  11. Thermal conductivity • Should a filling material have good thermal conductivity? • Thermal expansion • Is important when dissimilar materials will be fastened and heated, and when materials are locally heated. • Unit: in./in. oF or cm/cm oC • Example: Thermal expansion of restorative materials should match with that of teeth.

  12. Every dimension on the piece must be multiplied by the coef. of expansion factor!  Thermal expansion: Question

  13. Heat distortion temperature polymers • Water absorption polymers • Electrical properties • Magnetic properties • Gravimetric • Density • Specific gravity

  14. Mechanical Properties • The characteristics of a material that are displayed when a force is applied to the material. • Often require the destruction of the material for measurement. • “mechanical”  indicates the suitability of a material for use in mechanical applications e.g. parts that carry a load, absorb shock, resist wear,...

  15. Material Properties Metals Plastics Ceramics Composites

  16. It is necessary to understand what these properties mean, how they are measured, and how they should be compared in the selection process.

More Related