Project 13 Proposal, October 11 1

Project 13: Nanodispersion Strengthened Aluminium

Luke N. FischerFaculty Supervisor: Professor Rishi Raj

Co-Supervisor: Dr Atanu Saha

Department of Mechanical EngineeringUniversity of Colorado at Boulder

Project 13 Proposal, October 11 2

What is Nanodispersion Strengthened Aluminium?

Particle reinforced MMC. Nano-scale particle

distribution – mean particle diameter in the order of 10nm.

Particle matrix interactions occur on the atomic or molecular level.

System to be Investigated: Al-matrix/SiCN particles

SiCN ceramic derived from Ceraset© polymer precursor.

SiCN Particle

Aluminium Matrix

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Project 13 Proposal, October 11 3

Why Research Nanodispersion Strengthened Aluminium? Goal: To achieve

improved mechanical properties of composite compared with pure aluminium.

Relatively light weight of aluminium retained.

Particles stable at high service temperatures unlike aged hardened aluminium alloys (e.g. Al-Cu system).

Some potential applications: aerospace, automotive, sporting goods.

Project 13 Proposal, October 11 4

Plastic deformation in metals result of movement of dislocation lines under applied stress.

Key mechanism is Orowan strengthening:

Particles impede motion of dislocations

Goal: Finest dispersion possible.

How does Nanodisperion Strengthening Work?

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Project 13 Proposal, October 11 5

Basic Experimental MethodKey Points of the Experimental Method:1. A control sample (pure aluminium) for every dispersion

hardened sample.2. Microhardness principal method of characterization.3. Optical microscopy and/or TEM microscopy to be used.

Consolidation of Sample Using Powder Metallurgy:

Technique A: Mixing of fine powders then consolidated in heated uni-axial

press – initial composition 10% SiCN by volume.Technique B:

Ceraset depositions on aluminium granules via solvent evaporation, consolidated as above.

Project 13 Proposal, October 11 6

In Summary Motivation: To obtain improved mechanical

properties while maintaining weight advantage of aluminium;

Orowan strengthening mechanism: finer dispersion = higher strength;

Samples to be consolidated using “hot-press” powder metallurgy;

End goal is to publish conclusive results on Al/SiCN system.

Thank you for your time…