microstructural analysis

Welcome to Weiterstadt!

Dr. Michaela Schleifer, European Regional Manager, EDAX

The European team had a very exhausting but successful week last week. Some months ago, we discussed the possibility of holding a user meeting at our headquarters in Weiterstadt, Germany. During our stay in Wiesbaden it became a tradition to do at least one user meeting or workshop a year. Because of our move to Weiterstadt and the development of some new structure in the European organization, it took quite some time to plan another user meeting. In spring time, we discussed how to satisfy the different areas in Europe regarding language and also how to transfer information about new technology to our distributors. We finally decided that we should organize 3 different meetings during the week of October 15th. The first two days were for our German speaking customers in Europe, mid-week we invited our distributors and on the last two days we offered a user meeting for our English-speaking customers. There was a lot of organization to be done, like making hotel reservations, preparing presentations, organizing hosting and also booking nice restaurants for the evening events. All of us were a bit nervous about whether everything would work, whether we had forgotten anything important and whether our SEM and system would work properly. The week before the meetings we installed the Velocity™ camera, our new high speed EBSD system in our demo lab and our application people were very happy with the performance and had fun playing around with it.

On Monday October 15th we started our first user meeting in the Weiterstadt office at around 1 pm with customers from the German speaking area. Around 45 participants joined the meeting. At the beginning we gave an overview of our current products and explained that our complete SDD series is using the Amptek modules with Si3N4 windows. Based on some spectra we showed the improved light element performance. After that Felix, one of our application specialists, showed our new user interface APEX™ live and the discussion which arose showed the interest from our users. Although only some users are doing EDS on a TEM we explained a little bit about the differences between EDS on a TEM and on a SEM. We finished the first day with a question and answer session and invited all the participants to a nice location in Darmstadt to have a typical German dinner together.

The next day was completely dominated by EBSD. Our EBSD product manager Matt Nowell, who came from Draper, USA to support us during our meetings, demonstrated the performance of our new Velocity™ EBSD camera. Matt also explained the differences in the camera technology using CCD or CMOS chips and described direct electron detection. It was easy to get more than 3000 indexed points per second while measuring a duplex steel with the Velocity™ camera. Our EBSD application specialist René de Kloe presented a lot of tips and tricks regarding EBSD measurements and analysis of measurement too and did not get tired of answering all the questions. At the end of our program all participants left with a good feeling having learnt a lot and got some good ideas about how to improve their measurements or what they might try to measure on their own samples.

The next day we shortened our program for our distributors and explained our product range and gave live demonstrations of APEX™ software platform and the Velocity™ CMOS EBSD camera. This day was dominated by a lot of discussions with the group and also by questions about our roadmap for 2019.

On Thursday and Friday of this week we did the same program for our English-speaking customers in Europe as we did for the German speaking customers. We had around 15 participants.

During this week we had around 75 customers in our office in Weiterstadt. Each customer was different in his applications and how he uses our systems but what we could observe during the evening was that most of them are very similar in what they like for dinner:

Late on Friday evening the whole European team was very happy that we managed the week with all the meetings and that based on the feedback we got it was a successful week. You may be sure that all of us went home and had a relaxing weekend!

I would like to thank Matt, Rene, Felix, Ana, Arie, Rudolf, Andreas and Paul and especially our customers who gave some interesting presentations about their institutes and the work they are doing there.

Teaching is learning

Dr. René de Kloe, Applications Specialist, EDAX

Figure 1. Participants of my first EBSD training course in Grenoble in 2001.

Everybody is learning all the time. You start as a child at home and later in school and that never ends. In your professional career you will learn on the job and sometimes you will get the opportunity to get a dedicated training on some aspect of your work. I am fortunate that my job at EDAX involves a bit of this type of training for our customers interested in EBSD. Somehow, I have already found myself teaching for a long time without really aiming for it. Already as a teenager when I worked at a small local television station in The Netherlands I used to teach the technical things related to making television programs like handling cameras, lighting, editing – basically everything just as long as it was out of the spotlight. Then during my geology study, I assisted in teaching students a variety of subjects ranging from palaeontology to physics and geological fieldwork in the Spanish Pyrenees. So, unsurprisingly, shortly after joining EDAX in 2001 when I was supposed to simply participate in an introductory EBSD course (fig 1) taught by Dr. Stuart Wright in Grenoble, France, I quickly found myself explaining things to the other participants instead of just listening.

Teaching about EBSD often begins when I do a presentation or demonstration for someone new to the technique. And the capabilities of EBSD are such that just listing the technical specifications of an EBSD system to a new customer does not do it justice. Later when a system has been installed I meet the customers again for the dedicated training courses and workshops that we organise and participate in all over the world.

Figure 2. EBSD IPF map of Al kitchen foil collected without any additional specimen preparation. The colour-coding illustrates the extreme deformation by rolling.

In such presentations, of course we talk about the basics of the method and the characteristics of the EDAX systems, but then it always moves on to how it can help understand the materials and processes that the customer is working with. There, teaching starts working the other way as well. With every customer visit I learn something more about the physical world around us. Sometimes this is about a fundamental understanding of a physical process that I have never even heard of.

At other times it is about ordinary items that we see or use in our daily lives such as aluminium kitchen foil, glass panes with special coatings, or the structure of biological materials like eggs, bone, or shells. Aluminium foil is a beautiful material that is readily available in most labs and I use it occasionally to show EBSD grain and texture analysis when I do not have a suitable polished sample with me (fig 2) and at some point, a customer explained to me in detail how it was produced in a double layer back to back to get one shiny and one matte side. And that explained why it produces EBSD patterns without any additional preparation. Something new learned again.

Figure 3. IPF map of austenitic steel microstructure prepared by additive manufacturing.

A relatively new development is additive manufacturing or 3D printing where a precursor powdered material is melted into place by a laser to create complex components/shapes as a single piece. This method produces fantastically intricate structures (fig 3) that need to be studied to optimise the processing.

With every new application my mind starts turning to identify specific functions in the software that would be especially relevant to its understanding. In some cases, this then turns into a collaborative effort to produce scientific publications on a wide variety of subjects e.g. on zeolite pore structures (1, fig (4)), poly-GeSi films (2, fig (5)), or directional solidification by biomineralization of mollusc shells (3).

Figure 4. Figure taken from ref.1 showing EBSD analysis of zeolite crystals.

Figure 5. Figure taken from ref.2 showing laser crystallised GeSi layer on substrate.

Such collaborations continuously spark my curiosity and it is because of these kinds of discussions that after 17 years I am still fascinated with the EBSD technique and its applications.

This fascination also shows during the EBSD operator schools that I teach. The teaching materials that I use slowly evolve with time as the systems change, but still the courses are not simply repetitions. Each time customers bring their own materials and experiences that we use to show the applications and discuss best practices. I feel that it is true that you only really learn how to do something when you teach it.

This variation in applications often enables me to fully show the extent of the analytical capabilities in the OIM Analysis™ software and that is something that often gets lost in the years after a system has been installed. I have seen many times that when a new system is installed, the users invest a lot of time and effort in getting familiar with the system in order to get the most out of it. However, with time the staff that has been originally trained on the equipment moves on and new people are introduced to electron microscopy and all that comes with it. The original users then train their successor in the use of the system and inevitably something is lost at this point.

When you are highly familiar with performing your own analysis, you tend to focus on the bits of the software and settings that you need to perform your analysis. The bits that you do not use fade away and are not taught to the new user. This is something that I see regularly during the training course that I teach. Of course, there are the new functions that have been implemented in the software that users have not seen before, but people who have been using the system for years and are very familiar with the general operation always find new ways of doing things and discover new functions that could have helped them with past projects during the training courses. During the latest EBSD course in Germany in September a participant from a site where they have had EBSD for many years remarked that he was going to recommend coming to a course to his colleagues who have been using the system for a long time as he had found that the system could do much more than he had imagined.

You learn something new every day.

1) J Am Chem Soc. 2008 Oct 15;130(41):13516-7. doi: 10.1021/ja8048767. Epub 2008 Sep 19.
2) ECS Journal of Solid State Science and Technology, 1 (6) P263-P268 (2012)
3) Adv Mater. 2018 Sep 21:e1803855. doi: 10.1002/adma.201803855. [Epub ahead of print]

Endless Summer

Matt Nowell, EBSD Product Manager, EDAX

My family and I love the beach. We love to swim in the water, ride the waves, and play in the sand. Each summer we typically spend time at Sunset Beach, North Carolina. After years of seeing the cool stuff in the SEM, materials science and microscopy are always topics of discussion. This year, after enjoying the musical Hamilton, my wife was inspired to start working on a periodic table of elements rap song. My 13-year-old learned more about metalworking watching the History Channel show, Forged in Fire, where participants are challenged to make different weapons from assorted metallic sources. My favorite part was watching them evaluate different parts of a bicycle for heat-treatable steel to recycle. One of my favorite moments though was unpacking my beach shoes on the first day.

Generally, when we visit a beach, we try to bring home a shell or a piece of driftwood. However, when I was putting on my shoes for the first time, I noticed some sand was still present. My last beach trip had been to the Cayman Islands. I immediately noticed that this sand looked much different than the sand at Sunset Beach. I decided to save a little bit of each for some microscopy and microanalysis when I got back home.

When I looked at them both more closely, I saw that the sand from Sunset Beach (SB) on the left was much darker with black flecks, while the sand from Grand Cayman (GC) was much lighter. Thinking about the possible composition of the sand got me thinking about the bladesmithing competition held at the TMS annual meetings. One year, the team from UC Berkeley created a sword using magnetite found at local beaches using magnets. I thought it would be interesting to examine both of these sands with my SEM, EDS, and EBSD tools.

Sand grains from Sunset Beach
Sand grains from Sunset Beach.
Sand grains from Grand Cayman
Sand grains from Grand Cayman.

 

Initially I placed a bit of sand on an aluminum stub for SEM and EDS analysis. To reduce charging effects, I used the Low Vacuum capability of our FEI Teneo FEG-SEM, running at 0.1 mbar pressure. Images were collected using the Annular BackScatter (ABS) detector for atomic number contrast imaging. The sand grains from Sunset Beach were generally a little smaller than the Grand Cayman sand, as expected from visual inspection. Both sands exhibited cracking and weathering, which isn’t surprising in hindsight either. Many grains show flat surfaces, with internal structure visible with ABS imaging contrast.

I followed the imaging work with compositional analysis using EDS. The Sunset Beach sand was primarily composed of silicon and oxygen grains, which I suspect is quartz. The single brighter grain in Figure 3 was composed of an iron-titanium oxide. The Grand Cayman sand was primarily a calcium carbonate (Ca-C-O) material. The more needle shaped grains were primarily sodium and chlorine, which I assume is then salt that has solidified during the evaporation of the water. All this leads me to believe I really didn’t do a good job of cleaning my shoes after Grand Cayman.

While quartz being present in sand wasn’t surprising to me, the observation of calcium carbonate did remind me of some geological homework I did on the island. The water in Grand Cayman was very clear, which made it great for snorkeling. We swam around and saw a coral reef, a sunken ship, lots of fish, and stingrays. To understand why the water was so clear, I read that it was the lack of topsoil, and the erosion and runoff of topsail to the water that was responsible for the clarity. Looking again at this reference, it mentions that the top layer of the island is primarily composed of carbonates. The erosion of this material would explain the primary composition of the beach sand in my shoes.

Of course, the next step now is analyzing these sands with EBSD to determine the crystal structure of the materials. I’ve started the process. I’ve mounted some of the sand in epoxy, and hand polished to get some flat surfaces for analysis. I’m able to get EBSD patterns, but getting a good background is going to be tricky. I think the next step will be to watch my colleague Shawn Wallace’s webinar on Optimizing Backgrounds on MultiPhase samples to be presented on September 27th. You can also register for this here.

In the meantime, I’ll keep the sand samples on my desk to remind me of summer as the colder Utah winters will be approaching. It will be a good reason to stay inside and write the next chapter of this analysis for another blog post.

One, Two, Three Times an Intern

Kylie Simpson, Summer Intern at EDAX

Kylie ‘at home’ in the Applications Lab.

This summer was my third working for the EDAX Applications Team. It has been an amazing opportunity to be directly involved with research, customer support, and software testing here in Mahwah. I was able to continue with the APEX™ software testing that I worked on last summer which I found incredibly interesting because I’ve been able to observe the software evolve to best meet customer needs and improve in overall performance. I also had the chance to attend the Microscopy and Microanalysis (M&M) show in Baltimore, MD. This was an incredible experience for an undergraduate student, like me, interested in Materials Science and Microscopy. I was able to connect with people in the field, attend talks on topics at the forefront of Microscopy research, and present a poster that I have been helping out with this summer here at EDAX.

The majority of my time this year has been focused on helping Dr. Jens Rafaelsen, the head of the Mahwah Applications Team, with the data collection and analysis for a paper on the effects of Variable Pressure on EDS. Although Variable Pressure is an incredibly useful tool for studying SEM samples that are susceptible to charging, the introduction of gas to the specimen chamber has implications that must be considered when collecting EDS spectra. Additional gas particles in the SEM chamber lead to a scattering of the electron beam, known as beam spread or beam skirting.

In order to study and quantify this phenomenon, we used a double insulated Faraday cup with a 10 µm aperture, pictured below, to measure the unscattered beam at different pressures and working distances. We also modeled this beam scattering using Monte Carlo simulations that consider the SEM geometry as well as the type of gas in the chamber, which vary based on the type of SEM. Based on our experimental and theoretical results, we determined that as much as 85% of the electron beam is scattered outside of the 10 µm diameter high pressures of 130 Pa. This is much more scattering than we had anticipated, based on previous papers on this subject, making these results incredibly important for anyone using variable pressure in the SEM.

Double insulated Faraday cup with a 10 µm aperture.


Unscattered Beam Percentage vs. Pressure: Theoretical

Unscattered Beam Percentage vs. Pressure: Experimental

Overall, I am very thankful for the opportunities that EDAX has given me this summer and in the past. As a member of the Applications Team, I was able to work alongside the Engineering, Software Development, Customer Support, and Sales teams in order to help provide customers with the best analysis tools for their needs. I also gained a deeper understanding of the research, data collection, and analysis processes for writing a paper to be published: a truly incredible experience for an undergraduate student. Above all, the plethora of knowledge and experience of those here at EDAX and their willingness to share this information with me and others has been the most valuable aspect of my time here.

Down Memory Lane

Sia Afshari, Global Marketing Manager, EDAX

For years I have been attending the Denver X-ray conference (DXC) and it is hard when it coincides with the Microscopy and Microanalysis Conference (M&M) as it has a few times in the past several years. It is just difficult for me to accept that the overlap is not avoidable!

My interests are twofold, marketing activities where my main responsibility lie, and technical sessions which still pique my curiosity and which are beneficial for future product development. In the past couple of years at M&M, it has been great to attend sessions devoted to the 50 year anniversaries of electron microscopy, technical evolution, and algorithms, where my colleagues have either been the subject of presentations or have given papers. I have had the fortune to meet and, in some cases, to reacquaint with some of the main contributors to the scientific advancement of electron microscopy.

Being at M&M, I have missed the final years of attendance at DXC of the “old-timers” who have retired. These are gentlemen, in the true meaning of the word, whom I have had the honor of knowing for over 30 years and who have been more than generous with their time with me. I recognize most of all their devotion and contribution in advancing x-ray analysis to where it is today. Their absence will be felt especially in the development of methodology and algorithm. As a friend, who was frustrated with the lack of availability of scientists with a deep knowledge in the field, recently put it, “these guys don’t grow on trees.”

Back at M&M this year, I listened to Frank Eggert talking about the “The P/B Method. About 50 Years a Hidden Champion”, and he brought back many memories. I recognized most of his referenced names, and the fact that they are no longer active in the industry! Looked around the room, I saw more people of the same hair color as mine (what is left). I thought about the XRF/XRD guys I used to know and who are also no longer around the industry. The old Pete Seeger song popped up in my mind with a new verse as; “where have all the algorithmic guys gone?”

Vacationing Between a Rock and a Hard Place?

Shawn Wallace, Applications Engineer, EDAX.

One of the perks of both my degree (Geology) and my current job is that I have travelled extensively. In all those travels, I had been to 47 of the 48 contiguous US States, with Maine being the missing one. This year, I decided to be selfish and dragged the family to Maine on vacation, so I that could tick off the final one.

Being a member of the Wallace family means vacation is a time for strenuous hikes and beating on rocks to unlock their inner goodies, to add to our ever growing rock and mineral collection. This vacation was no different. Maine is home to some of the best studied and known Pegmatites, and they quickly became our goal. Pegmatites are neat for a several reasons, the main two being that they tend to form giant crystals (a 19 foot long Beryl found in Maine) and weird minerals in general tend to form in them.

I was able to track down some publicly accessible sites, found a lovely home base to rent for the week, and we set off for a week long rockhounding adventure. Ok not all week. We took a couple days off to go swimming, as it got up over 90F (>32C).

Figure 1. Dendrites cover this massive feldspar sample on nearly all faces.

Our first stops yielded the usual kind of rocks I was expecting, but another site did not. There we found dendrites everywhere. The rock itself is a massive feldspar (Fig. 1). You can see that most of the dendrites nucleate at the edge of a fracture surface and then do their fractal thing on the surface itself. Wanting to better understand the sample, I started searching for previous EBSD work on geological dendrites. While a lot exists in the metals world, very little exists in the geological world. To me, this means I have work to do. Let’s see what I can do to get some useful data on this sample!

P.S. I have Alaska and Hawaii to go. Who needs an onsite training in those states? 😉

Countdown to M&M…..

Patrick Camus, PhD, Director of Engineering, EDAX

This time of year is, at least in the US, preparation time for the Microscopy and Microanalysis (M&M) meeting. Like most big shows, every attendee has a significant amount of preparation to perform in the weeks (days?) leading up to their travel date. Most readers of this blog will be platform or poster presenters. You may be under stress to collect that last set of experimental data to fill that last hole in the analysis to finalize your presentation.

Life is not so different for the commercial exhibitors like EDAX. Unknown to the general participants, there are many departments under similar pressures to ensure a productive meeting for all attendees. Engineering is applying the finishing touches to new products. Software Engineering is approving the latest versions of software for release. Marketing Communications is contacting current and prospective customers to attend equipment demos and workshops during the exhibition hours. Marketing is receiving the final graphics of product literature for decorating the booth. Service is scheduling engineers to install all the EDAX microanalysis systems in our booth and those of our electron microscope associates. Applications scientists are finalizing their presentations for the meeting but also for the demos and EDAX workshops to be performed in our booth. Logistics is coordinating the hotels for our employees and shipping our equipment both to and from the venue. About the only employees not under stress before the meeting are Sales who coast now but are under the most stress (or is it strain) during the week of the show.

The exhibitors may seem very relaxed to the visitors during the show, but that image derives from the total effort that they are putting forth now so that you have the best experience possible.

We look forward to seeing all of you in Baltimore, or your next show!

Click here for more information about EDAX at this year’s event.