Mission Statement

Understanding engineering and functional materials behavior under complex environments.

Instrument Description

VULCAN is designed for deformation, phase transformation, residual stress, texture, and microstructure studies. Load frames, furnaces, battery chargers, and other auxiliary equipment for in situ and time-resolved measurements are integrated in the instrument. As a time-of-flight diffractometer at the world's most intense pulsed, accelerator-based neutron source, VULCAN provides rapid volumetric mapping with a sampling volume of 2-600 mm3 and a measurement time of minutes for common engineering materials. In extreme cases, VULCAN has the ability to study kinetic behaviors in sub-second time frames.

Applications

VULCAN covers a broad range of applications in materials science and engineering, from residual stress determination in engineering components to understanding the fundamental aspects of material behaviors during synthesis, processing, and service. Research areas that can benefit of VULCAN include but are not limited to the following:

  • In situ studies of materials behavior during processing or synthesis: phase formation, temperature distribution, texture changes, stress development, precipitation.
  • In situ loading studies of crystalline/amorphous materials at high temperatures: phase transformation, fatigue damage, creep behaviors, and other deformation mechanisms in nanostructured materials, piezoelectric and shape-memory alloys.
  • In situ/operando studies of working system such as batteries and hydrogen storage devices.
  • Nondestructive residual stress, texture, and microstructure investigation in engineering components.

Specifications

Selectable chopper speed and bandwidth: 60 Hz, 1.44 Å; 30 Hz, 2.88 Å; 20 Hz, 4.32 Å ( for measurable d range in 90 degree detectors, divide the bandwidth by 1.414). ~0.35Å < d-spacings <~4 Å.
Sample stage: Rotation: 360°, X,Y, +/-250 mm, Z +/-300 mm. Weight capacity: 2000 kg. Positional precision: < 25 μm for loads < 200 kg; 100 μm for loads between 200 and 2,000 kg. Standalone horizontal and vertical rotation motors.
Detector: +/-90° 3He linear-position-sensitive detectors (LPSDs), measure two orthogonal strain components simultaneously, and 150° high angle detector for high resolution applications. Optional down stream MCP detector for transmission measurement of ~150 micron spatial resolution. 
High-intensity and high-resolution exchangeable guides: For 90 degree banks, ~0.45% (HI) and ~0.25% (HR) Δd/d resolution. For high angle detector ~0.10% for both modes. (Q dependence can be found in the User Guidance page)
Beam size 0.5-12 mm horizontal and 0.5-12 mm vertical incident slit. 2 mm and 5 mm receiving radial collimators.

Sample Environment Capabilities

The open space of the instrument can host a variety of sample environments to provide flexible capabilities for broad research. Below are the short list of the capabilities. We also accept user's sample environments or special setups. Sample preparations and offline characterizations are also available via SNS users lab, such as microscopy, x-rays, DSC etc.

1. Dedicated in-situ mechanical loading with VULCAN MTS Loadframe, +/-100KN tension/compression, and 400Nm torsion, +/-100mm stroke, 270o rotation. Centroid control.  30Hz rated cyclic loading, and uniaxial movement as low as 10-6 mm/s. Induction heating in air with loading. Temperatures limited by materials oxidation resistance and induction coupling.

2. Resistive heating furnace with gas enclosure (RHEGAL), 300A DC.

3. Battery cycler, +/- 5V, various current range including large current booster up to 100A. Electrochemical Impedance Spectroscope. 10KV HV AC fields - that can be coupled with mechanical loading. 

4. Bottom mount controlled atmosphere furnace from SNS/HFIR sample environment pool, ambient to 1500oC.

5. Bottom mount ILL vacuum furnace from SNS/HFIR sample environment pool, ambient to 1600oC.

6. Liquid N2 cooling jar free heat from -80K to ambient.

7. Other standalone sample environments such as cryogenic furnaces can be found in SNS sample environment pool. Check with instrument team for details.