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Compact vs. High-End EBSD Systems: A Performance Comparison of Detector Technologies

Yifan Jiang – PhD, Applications Scientist – JH Technologies

Bruker EBSD Detectors

Need help with prep? Read our guide to EBSD sample preparation.

Electron backscattered diffraction (EBSD) is a powerful technique for understanding material crystallography, including crystal orientation, grain size analysis, phase identification, and strain analysis. Although several factors affect EBSD detection, the EBSD detector plays a key role in capturing the Kikuchi pattern during analysis. This application note showcases two different EBSD detectors from Bruker and their effect on crystallographic results.

Introduction

An EBSD detector usually consists of the following components: a phosphor screen (scintillator), lens or fiber optics, and a sensor. The phosphor screen converts the electron signal to a photon signal (Kikuchi pattern). The lens focuses the light into the sensor, and the sensor detects and records the photon signal.

Over the past several decades, EBSD development has focused on speed and signal sensitivity, with one of the improvements being the development of direct electron detection. Direct electron detection technology allows backscattered electrons to be collected directly by the pixelated image sensor without a scintillator, avoiding additional conversion of electrons into photons before collection. With direct electron detection, faster EBSD data collection is possible.

Bruker is one of the world’s leading manufacturers of EBSD detectors, offering a wide range of detectors for different applications. In this paper we examine two different EBSD detectors to show the similarities and differences between them.

The Bruker eFlashXS detector is the ED-XS system that can be mounted on compact SEMs such as the Coxem CX-300 and EM-40. The detector features a CMOS sensor and a native resolution of 720×540. This is the most affordable and compact EDS/EBSD system; it is small, light, and easy to operate. We have the eFlashXS  installed on our tabletop COXEM EM-40 and compact CX-300 SEM as well.  COXEM is the first company to install  EBSD detectors on a tabletop SEMs.

      

Bruker eFlash XS installed on Coxem EM-40

The other system is Bruker’s latest EBSD detector, eWARP, which uses a wide-area, pixelated detector. With direct electron detection technology, the eWARP detector enables high signal sensitivity, faster acquisition, and enables low-kV EBSD capability. The eWARP system is installed in our CIQTEK 5000X FE SEM, a high-resolution FE SEM with a large chamber.

Bruker eWARP installed on CIQTEK SEM5000X FE SEM

Objective

The objective of this study is to compare the performance of the eFlash XS and eWARP EBSD systems, highlighting their similarities and differences in crystallographic analysis.

Results and Discussion

Figure 2 shows an SEM image of the duplex steel after polishing. The BSE image clearly shows the grains with different contrast.

Figure 2: BSE image of the duplex steel surface after sample preparation.

To get a more direct comparison between the two EBSD systems, we use similar imaging conditions at 20kV on the SEM and a similar EBSD step size to get the grain information.

The comparison of the two EBSD acquisitions is shown in Table 1. Good sample preparation ensures that the indexing rate on the duplex steel between the two systems is high and identical. With a similar EBSD step size and the same map size, acquisition on eWARP is more than 40 times faster than eFlash XS EBSD, given its sensitive detector.

Table 1: EBSD mapping acquisition comparison between eFlash XS and eWARP EBSD detector

Figure 3 shows the results obtained using the eFlash XS EBSD detector, including (a) EBSD pattern, (b) pattern quality with phase map, (c) phase analysis, (d) grain map, and (e) grain distribution analysis. This compact eFlash XS EBSD detector is capable of generating full analysis on materials despite a slightly longer acquisition time.

(a)     (b)

(c)

(d)

(e) Figure 3: EBSD analysis on duplex steel using eFlash XS detector. Acquisition was performed on COXEM CX-300 compact tungsten SEM. (a) EBSD pattern, (b) pattern quality with phase map, (c) phase analysis, (d) grain map (e) grain distribution analysis

Experimental Procedure

A commercial duplex steel sample was prepared using Buehler sample preparation equipment, including:

  • IsoMet High Speed Pro precision sectioning saw
  • SimpliMet 4000 hot mounting system
  • EcoMet 30 semi-automatic grinder-polisher

After polishing to a 0.05 μm finish, the sample was ion-milled at 3.5 kV using a Leica  ion mill to remove residual surface stress. Ion milling is a critical step that significantly improves EBSD data quality and indexing accuracy:

  1. Leica EM TIC3X ion millEM Sample Preparation Systems 

The sample was analyzed using:

  • A COXEM CX-300 tungsten SEM with an eFlash XS EBSD detector
  • A CIQTEK 5000X FE-SEM with an eWARP EBSD detector

Figure 4 shows the results obtained using the eWARP EBSD detector, including (a) EBSD pattern, (b) pattern quality with phase map, (c) phase analysis, (d) grain map, and (e) grain distribution analysis, and (f) VFSE image.

With this sensitive EBSD detector, all statistical analyses can be performed with great precision within 1:44min, enabling fast routine EBSD analysis. The VFSE image is generated simultaneously with EBSD acquisition, revealing details of the grain structure.

(a)     (b)

(c)

(d)

(e)

(f)

Figure 4: EBSD analysis on duplex steel using eWARP detector. Acquisition was performed on CIQTEK 5000X FE SEM. (a) EBSD pattern, (b) pattern quality with phase map, (c) phase analysis, (d) grain map (e) grain distribution analysis (f) VFSE image

Another great advantage of the eWARP EBSD detector is its capability to perform analysis at low energy. Figure 5 shows the EBSD analysis on the duplex steel using eWARP at 10kV (a) pattern, (b) pattern quality with phase map. The EBSD analysis of the same map size can be completed within 2:12 min, with 93.9% indexing rate. Low-energy EBSD provides better spatial resolution for grain analysis due to the smaller interaction volume. This is beneficial for small-grain analysis and reduces beam damage on sensitive materials.

 

(a)     (b)

 

Figure 5: EBSD analysis on duplex steel using eWARP at 10KV. Acquisition was performed on CIQTEK 5000X FE SEM. (a) EBSD pattern, (b) pattern quality with phase map

Summary

This study demonstrates that both the eFlash XS and eWARP EBSD detectors are capable of delivering accurate and reliable crystallographic analysis despite the detector’s sensitivity differences.

Key Findings include

  1. Both eWARP and eFlash XS EBSD detectors provide the capability for microstructure and grain analysis on crystalline samples. The indexing rate is comparable at high energy conditions for both systems.
  2. With a more sensitive detector, eWARP allows ultrafast data acquisition, more than 40 times faster than the eFlash XS detector. This is beneficial for fast turnaround on routine EBSD analysis.
  3. The eWARP detector also allows low-energy EBSD detection without compromising on speed, enabling higher EBSD spatial resolution due to a smaller interaction volume. This is also beneficial for sensitive materials on EBSD analysis.
  4. This study demonstrates that both the eFlash XS and eWARP EBSD detectors are capable of delivering accurate and reliable crystallographic analysis.

The choice between systems should be guided by application requirements, including throughput, resolution, and budget.

Cost Considerations

Above we provided a technical assessment of the different EBSD capabilites. Here is a real-world cost example:

  1. Table-top or Compact SEM with EBSD /EDS starts at approximately $200K
  2. Full-size FE SEM with high speed EBSD/EDS starts at approximately $500K

Systems are available at intermediate price points depending on configuration and performance requirements.

For detailed pricing or system demonstrations, please contact us.

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