Microscopy and Microstructure Analysis

I- Purpose/Objective:

Microstructure analysis is a core technique in Materials Science. Here we will introduce the techniques of optical microscopy and scanning electron microscopy, and use these instruments for the analysis of the microstructure for several materials. Some specific objectives are:

  1. Skill development for bulk specimen preparation, metallographic polishing and etching to reveal microstructure, digital image capture via optical microscopy.

  2. Principles of optical microscopy and training on MSE 360 Nikon optical microscopes.

  3. Introduction to Scanning Electron Microscopy and microstructure interpretation.

  4. Quantitative microstructural analysis by manual methods

  5. Automated digital image techniques for quantitative microstructural analysis.

  6. Statistical analysis of aggregate data to determine standard deviation, confidence levels and accuracy.

  7. Skill development in constructing technical reports.

The emphasis will be on the proper preparation of a sample, the proper techniques for acquiring an image, and the interpretation of features in the image.


II - Experimental Procedure:

The unit is organized into several activities, each a different task. Since we only have limited facilities, you will conduct these tasks in no particular order.

Activity 1: Optical Microscopy

Objective: To learn the functions of the Nikon Optiphot microscope for reflected and transmitted light microscopy.

Outcome: Obtain images of CuP for further analysis.

    Activity 2: Quantitative Analysis

    Objective: To learn quantitative image analysis using standard image processing software

    Outcome: wt% and grain size determination of CuP


      Activity 3: SEM

      Objective: To learn scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS)

      Outcome: Obtain images of CuP for futher analysis and determine compositions of different features in the microstructure

       

      Activity 4: Metallographic Sample Preparation

      Objective: To learn sample mounting, grinding and polishing.

      Outcome: Prepare a metal (ductile cast iron, Al alloy, etc.) sample for further analysis

        Activity 5: Characterize Individual Sample

        Objective: To apply skills learned in Activities 1-4 to characterize your own sample.

        Outcome: Full microstructural analysis will be written up in a formal individual report.


        III - Theory/Background Information:


        IV - Theory/Background References:

        The following references are suggested reading for Microsctructures Laboratory:

        1. E.E. Underwood, "Applications of Quantitative Metallography," Metals Handbook, 8th ed., vol. 8, p.37. (in 2235 HH Dow)
        2. "Atlas of Microstructures of Industrial Alloys", Metals Handbook, 8th edition, vol. 7. (in 2235 HH Dow)
        3. “Metallography and Microstructures,” Metals Handbook Ninth Edition, Vol.9, American Society for Metals, 1985. ISBN 0-87170-007-7 (In 2235 H. H. Dow)
        4. A Simplified Guide to the Use of Reflective Light Microscopes (LECO Corp.)
        5. Manual point count.pdf
        6. Grain Size determination.pdf
        7. Metallographic Sample Preparation by A. Johnson (LECO Corp.)

        V- Activity Schedule:

        Date/Time        
        Group 1
        Group 2
        Group 3
        Group 4
        Day 1
        first half

        1:30-3:30

        Activity #1
        microscope
        Activity#2
        image analysis
        Activity#3 
        SEM
        Activity#4
        metallographic
        preparation
        Day 1
        second half

        3:30-5:30

        Activity#2
        image analysis
        Activity#3 
        SEM
        Activity#4
        metallographic
        preparation
        Activity#1
        microscope
        Day 2
        first half

        1:30-3:30

        Activity#3 
        SEM
        Activity#4
        metallographic
        preparation
        Activity#1
        microscope
        Activity#2
        image analysis
        Day 2
        second half

        3:30-5:30

        Activity#4
        metallographic
        preparation
        Activity#1
        microscope
        Activity#2
        image analysis
        Activity#3 
        SEM
        Day 3
        first half

        1:30-3:30

        Characterize
        Individual 
        specimens
        Characterize
        Individual 
        specimens
        Characterize
        Individual 
        specimens
        Characterize
        Individual 
        specimens
        Day 3
        second half

        3:30-5:30

        Characterize
        Individual 
        specimens
        Characterize
        Individual 
        specimens
        Characterize
        Individual 
        specimens
        Characterize
        Individual 
        specimens

        VI -Format and Important Questions for Lab Report:

        Following the format suggested in the Lab Manual, write a lab report that clearly describes the objective of the experiment, the experimental results, and the conclusions you can reach, based on your experimental data and observations. Provide all the necessary data and appropriately reference the work you did to produce your data and reach your conclusions (what page nos., appendices, graphs, etc.). Refer to the handouts and lecture notes on report writing to help guide you in your efforts. As always, S.I.units must be used lab reports, figures and tables. The lecture period will cover the results you should have and the expectations for the first laboratory report.