Practice Makes Perfect
Dr Michael Shakib
24 September 2019
Attending a practical course can be an effective way of really getting to grips with a subject.
So, as a lecturer, there I am at the front of the class, PowerPoint presentation poised; a room full of industrious students waiting with baited breath for a masterclass in metallurgy!
I begin teaching, talking about phase diagrams and microstructures until even the keenest student plunges into the depths of confusion and frustration. You see, metallurgy is one of those subjects that doesn’t lend itself well to being absorbed in a classroom. It's definitely not unique in that respect; after all, would you ever be able to learn how to drive a car by sitting at a desk? Probably not – although the theory test does have its place. And so, it is the same for metallurgy – the theory needs to be complimented with a trip to the laboratory!
The students walk in, perhaps slightly confused with their new-found knowledge- the information sinking in but not quite there yet. Then it’s time to get the lab coats on.
First, we take a piece of steel and pull it apart, aka a tensile test, following which it's off to the metallography lab where we cut the steel with a hacksaw (always fun), then mount in resin (how many types of resins are there and why?). Next we head to the grinding wheels to make spinning tops - anyone who has done this for the first time knows what I am talking about. Finally, we start to polish; a mirror finish is our goal but at every stage there’s potential to do more damage and be back at square one (like a cruel game of snakes and ladders)!
At the fume cupboards we dip our freshly polished sample into a dish of acid to etch the surface, or potentially permanently destroy our hard work. Given how many variables are at play here – chemistry, temperature, time and luck, it all has to be done right.
The highlight of the course is often when the students get to the microscopes. Our beautifully prepared sample is put on to the stage and brought into focus. And there it is, the eureka moment! Staring the student right in the eyes is the microstructure that we predicted the day before on the slides. The mists of ambiguity dissolved away by the light of the microscope, and a previously incomprehensible concept is now understood.
If you are anything like me, then a concept does not become totally believable unless it is seen, touched or sensed in some way. And this is the power of combining theoretical learning and reasoning with practical hands-on exercises.
Here at Project METaL we are always looking for opportunities to add more practical activities and participatory exercises to our courses, with the aim of helping our students feeling more engaged, happy and fulfilled. This approach makes the subject matter easier to both learn and teach!
To learn more about my Practical Metallurgy course, click here.