Tensile Testing Masterclass Martin Carr (Schools Liaison Officer) Department of Materials Parks Road Oxford OX1 3PH Tel

Aims To raise awareness of Materials Science to schools. To encourage closer contact between schools and Materials Science Departments. To enable schools to have access to expertise and equipment that is beyond the reach of most schools.

Pedagogy - Preliminary Teachers should introduce Tensile Testing, strss – strain charts and relevant terminology BEFORE the Masterclass. –Plasticine and sand “Model” –Preliminary Experiments

Pedagogy - Preliminary Plastic behaviour of metals is modelled by the plastic behaviour of plastic-ine. “Sand” mimics the effect of carbon Measurements and observations can be made. –The “Feel” of the stress-strain chart. –Fracture surface appearance. –Necking. –Ductility.

Pedagogy - Masterclass Tensile Test Specimens are broken. Measurements and Observations are made and compared to % C content… –% increase in length –% reduction in area –Microstructure –Hardness –Strength

Results: Stress-Strain Charts

Results: Mechanical Properties

Overview Initial learning curve is very steep. Students split into groups of about 4 –Team work –Allocation of responsibilities –Collection of data. –Some, not all, students get good results. Data from each group is collected at the end of the session and copied onto a USB memory stick for the teacher to take away together with specimen data.

Benefits To The School Experience of working in an undergraduate teaching lab on a cut-down undergraduate experiment. Interaction with student demonstrators. Concrete experience of an abstract part of a teaching course. Teacher could use data for coursework. Links with the department which could be developed further.

Benefits To The Department One aspect of Materials Science is highlighted. Opportunity to raise awareness further Links with teachers may result in more sixth formers considering Materials Science as a career. Can be linked with “Aspiration” / “Gifted and Talented” and similar initiatives. Promotes Physical Sciences and Engineering on a broader basis.

Materials Used Material Supplier… Orchard Materials Ltd Unit 7, Brunel Way Thornbury Industrial Estate, Thornbury Bristol BS35 3UR Remko Iron0.02%C 080A150.18%C 080A420.41%C 070M550.54%C S %C Heat Treatment – in House Normalise all steel in the same way… Heat in the furnace and hold at 860˚C for 1 hour. Remove from furnace and air cool out of draughts.

Engineering Supplies CNC Machining Jacobs and Sons Unit 6, Park Farm Industrial Estate Greet Gloucestershire, GL54 5BX For bulk orders, machining approx. £1.55 to £1.65 each.