The ZapperBox

1) Fracture Marking


Conventional fracture marking methods  (High R-ratio blocks) do not work well with metals like Ti, nor at near threshold conditions.


Local Heat Tint using electric pulse promises good observability in heat- tintable materials all the way down to threshold levels.

2) Local Heat Tint Technique

4) Proof of Concept: High Amp Pulse in Ti Foil

Digitally enhanced tint colors from oxide layer film.

8) The Takeaways

Tint radius 0.14 inch—100x larger than required to mark.

Asymptotic Electrothermal solution developed to enable temperature control.


•Local current density with 1/√r singularity at tip

•Local resistance heating proportional to 1/r

•Steep linear temperature gradient near tip

•Can be tailored to size local tint zones

3) Electrical Field Analogous to Mode III

Analogous to deformation, we can express the singular voltage field in terms of a scalar multiplier.

5) Crack-tip Temperature Control

•Franc3D/Mode III handbook solutions used to obtain KE solution.

•Steady-state thermal solution depends on external boundary conditions.

•Local Transient thermal solution insensitive to external boundary conditions.

•High-Amp transient electric pulses renders local thermal response largely geometry independent for given (KE, tpulse), and enables sharp tint lines.

•KE and transient thermal solutions built-in to FractureLab software to enable precision crack tip heating/local tinting for common specimens.

6) System Architecture & Schematics

•4000 Amp, precision pulse capability

115 lbs, 19”inch rack mount or wheels

Windows compatible software

9) Flagship Products & Services

Portfolio of products for exploratory research requiring High Ampere, Short Duration Pulse

•Series 4000 for Entry Level Marking

•Series 5000 for Premium Marking Capability•Custom Configuration for Special Application

•Fully supported with Consulting Services 

Franc3D updated to obtain accurate KE

Possible Applications

•Crack growth threshold testing.

•Study of microstructural fracture mechanism.