Investigation of a bullet impact

December 1st 2010Engineering 45

Fall 2010Kevin Chee

Shauna FongMax Heald

• The Purpose• The Setup• The Results

Purpose

In this experiment our goal was to investigate the effects of a bullet impacting different materials. We accomplished this by cross sectioning the material at the bullet impact site then looking at the microstructure.

Setup• Material Preparation: – Steel: (2 thin, 2 thick)• 1 of each thickness, heated to 900⁰C then furnace

cooled• 1 of each thickness, heated to 900⁰C then quenched to

room temp

– Brass: • 1 sample 25% CW• 1 sample 0% CW

• Gun used: 22 caliber rifle

• Range: ~10 ft

• Mount: materials were mounted on single wooden board via zip-ties.

Thin steel furnace cooled impact

Thin steel quenched impact

Brass 25% CW

Brass w/o CW

Impact (head on)

Impact (side view)

Thick steel

Thin Steel (quenched) Thin Steel (furnace cooled)

Brass no CWBrass 25% CW

Furnace cooled steel Microstructure: using Nital etching solution

Impact direction

Furnace cooled steel Microstructure #2

Furnace cooled steel Microstructure #3

Furnace cooled steel Microstructure: using FeCl3 etching solution

Furnace cooled steel Microstructure: using FeCl3 etching solution #2

Quenched steel

Quenched steel

Quenched Steel

Brass no CW microstructure

Brass 25% CW

Shotgun slug vs Bulletproof vest

Aknowledgements

• Thanks to Johnson’s winery in Alexander Valley for letting us use their location.