# Minor Specialization Project

> Compared specific wear and surface damage in recycled PET and a 10 wt.% graphene grade through 18 pin-on-disc tests at MIT Manipal, with Sohan Kumar Y.

- Role: Materials Engineering · Mini project
- Year: 2025
- Page: https://madhavsonkusare.com/work/minor-specialization/

## Achievements

- 18 pin-on-disc tests · ASTM G99
- rPET vs 10 wt.% graphene
- Materials Engineering minor, MIT Manipal

## The experiment

We tested 6 mm specimens against a steel disc at three loads and three speeds. Each run covered 250 m; specific wear rate was calculated from mass loss.

Pins were cast in an aluminium mould heated in a salt bath, then mounted in a two-part 3D-printed PLA holder. Each was cleaned and weighed before and after testing.

- Figure: The specimen and its wear track on the laboratory tester.
- Figure: An aluminium mould heated evenly in a salt bath.

## The results

At 30 N and 480 rpm, the measured specific wear rates were 2.7 × 10⁻⁴ mm³/N·m for plain rPET and 7.7 × 10⁻³ for the graphene grade.

Graphene wore more at every load at 320 and 480 rpm, but less at 160 rpm with 10 or 20 N.

- Figure: Plain rPET · all nine conditions
- Figure: rPET + graphene · all nine conditions
- Figure: Both materials · the complete comparison

## Two kinds of damage

The plain rPET specimens showed softening, smearing and embedded debris.

The graphene-grade specimens showed grooves, cracks and peeled layers, with less visible distortion.

- Figure: Plain rPET · 30 N / 480 rpm
- Figure: With graphene · 30 N / 480 rpm

## The takeaway

Wear response varied with load and speed. Mass loss and microscopy showed different damage mechanisms in the two materials.

One run per condition. No friction or temperature measurements. Further testing is needed before selecting either for a working part.

## Credits

Madhav Sonkusare and Sohan Kumar Y · Materials Engineering minor · MIT Manipal · November 2025.

Guide: Dr. B. Shivamurthy. Testing: Advanced Material Testing Laboratory, MIT Manipal.