Metallographic Laboratory
Course Name:
Metallographic Laboratory (MT377)
Programme:
Semester:
Category:
Credits (L-T-P):
Course Outcomes:
Students:
CO1: should know the techniques of grinding, polishing, mounting and etching for metallographic inspection
CO2: should know the expected phases and to identify them in steels, stainless steels, tool steels, cast irons, Al-Si alloys, babits, bronzes and brass
CO3: should know the different types of inclusions in steels
CO4: should be able to estimate phase fractions in hypo-eutectoid steels by basic image processing tools using ImageJ software
Course modules and teaching hours:
MODULE 1 (5 hours): Grinding and polishing techniques for metallographic sample preparation, mounting techniques hot and cold, etchants, etching techniques, identification of under-etched and over-etched conditions, contrast in optical microscopy, bright field and dark field (enhancement of contrast)
MODULE 2 (20 hours): Inclusion analysis on unetched specimens, examination of etched microstructures to identify grains, grain shapes, phases, twins in steels, stainless steels, cast irons, tool steels, aluminum alloys, copper alloys, Pb-Sn alloys, Ti-64, IN 718, Co-WC
MODULE 3 (5 hours): Etchant preparation: Nital for steels, Marble’s reagent and Carpenter’s reagent for stainless steels, Kroll’s reagent titanium alloys, Ferric chloride solution for copper alloys. Example of using image processing using ImageJ to measure phase fractions