MMC HammerEdward Barnard

Jenny Lichter

Elizabeth Hager

Kevin McComber

3.082

February 12, 2004

Overview

What are MMCs? Design Parameters Project Goals Setup Diagram Device Picture Prototype Design Testing and Imaging Projected Work Schedule

What are MMCs?

Metal Matrix Composites Benefits:

– High modulus from ceramic– High toughness from metal matrix– Lower density leads to high specific strength

Methods of Fabrication:– Stir Casting– Pressure infiltration (gas, mechanical, centrifugal)

Ceramic – metal reactivity– Can be optimized to yield strong bonding between

components

Jessada Wannasin's PhD thesis

Design Parameters

P = ( ½ ) * (ρω2) * (z22 – z1

2)

P = pressure, ρ = density of metal

ω = angular frequency, z = horizontal position

Pth ( * Vf,c ) / (Dc * Vf,m) = surface energy of the liquid metal

Vf,c = volume fraction of ceramic

Vf,m = volume fraction of the metal

Dc = size of ceramic particles

z1 z2

Project Goals

Materials choice– Metals: Tin-lead, Aluminum alloy– Ceramics: SiC, TiC, WC, Al2O3

Part production– CAD design– Mold fabrication and filling

Investment casting with a ceramic mold Steel machined mold Ceramic preform

Volume Fraction – Maximization through size distribution of ceramic particles – Gradation of properties through localized ceramic type and

density variations

Setup Diagram

Above: Top View

To Left: End View

Device Picture

Koczak, "Structural Composites," and "Thermal Composites"

Prototype Design

Part of an engine– Piston– Crank shaft

Propeller Hammer head Steel-toe boot Armor Bicycle crank Golf club Tools

Testing and Imaging

Testing Mechanical Properties– Specific strength – Hardness – Impact testing– Fracture resistance

Microstructure Analysis– SEM– Optical Microscopy

Projected Work Schedule

2/5 2/12 2/19 2/26 3/4 3/11 3/18 3/25 4/1 4/8 4/15 4/22 4/29 5/6 5/13Materials

Metal choiceCeramics choice

Part productionCADInvestment casting

Steel machined mold

Ceramic preform

Volume fraction Time PermittingSize distribution "

Final testing

CODE:Task Sub-task Gradation Testing

Works Cited

Koczak, et al. “Metal-Matrix Composites for Ground Vehicle, Aerospace and Industrial Applications.” Fundamentals of Metal Matrix

Composites. Boston: Butterworth-Heinemann, 1993. Eds. Suresh, S., Mortensen, A. and A. Needleman. 297-326.

Mortensen, Andreas. “Melt Infiltration of Metal Matrix Composites.” Comprehensive Composite Materials 3.20 (2000): 521-54.

“Structural Composites.” MMCC: Metal Matrix Cast Composites. Accessed 8 Feb 2004. <http://www.mmccinc.com/>.

“Thermal Composites.” MMCC: Metal Matrix Cast Composites. Accessed 8 Feb 2004. <http://www.mmccinc.com/>.