Nature of Science

On this page I will tell you about my day and those events that I think could called scientific experiences. At TiDA there are many different types of technology and behind these things there are many scientific processes and research projects taking place. I am going to try to focus on these but first I thought I would show you some of the technology used most of the time.

A SLM machine,test bars being laser printed and the furnace for heat treating metal.

1. Above are some of the complex machines that make the three dimensional printed products in Titanium and Stainless Steel.


2. Then there are many machines that clean, polish and finish the Titanium products.

Scanning Electron Microscope, Universal Testing machine, Laser particle sizer.

3. Finally (above) are some of the scientific instruments that test and check the finished Titanium products. These make sure they are perfect before they are sent to the customer.

My Very Own Experiment

I have been busy helping out with an experiment over the last few weeks. It has to do with mixing very fine titanium powder with several other special ingredients to form a plastic like substance that can be squeezed into a mould to make titanium metal objects.

I soon found out that creating the right combination of ingredients can be quite tricky so it has taken some time to find a recipe that may work properly. I did say MAY as in science you are never certain it will work out properly until you have completed the experiment several times and checked the results to see if things have turned out as you expected.

Lucky for me there is a lot of helpful information available so I have been able to read through all this to help me with my ingredients and mixing. The scientific papers were given to me by Dr Aamir, Dr Warwick and Dr Peter and I was encouraged to read them very carefully and then take notes on the important bits. The information was a bit like reading a recipe book written by an expert baker although this recipe contained materials that were not edible and were called by long complicated names.

Sometimes I needed to ask one of the scientists to explain things as these new ingredients reacted in strange ways when combined together and I had to ask for help to understand why things happen this way. However before I asked someone I would try to Google the answer first and sometimes I was able to figure things out for myself. If I still could not understand I would ask for help and the scientists at TiDA would explain it to me. They often used examples that we see and experience in our daily lives which help me understand what they were telling me. That was a big help.

However the people who have written down these recipes are scientists. These men and women have spent a lot of time and worked really hard to create these chemical mixtures. Reading through the experiments that they wrote down has made it possible for me to follow along with their way of doing things. So really I am just copying what they have done and with some advice from the experts at TiDA I have make some small changes to the mixture.

Once I had decided on the proportions the ingredients were heated slowly up to 100 degrees and mixed rapidly together. This took over two hours before I was confident from observing the mixture that it had combined properly and was runny like liquid honey is.

Then I had to move quickly as I needed to spoon the mixture into round balls and let them cool down slowly in a steel tray. If I had put them onto a kitchen bench they would have burnt it as they were still really hot.

After all the excitement was over I was left with a plastic bag full of balls of titanium powder combined with my secret recipe. My next job after that was to turn them back into powder again by using a big silver grinding machine. This had a long handle that I had to turn to make a blade inside cut of the titanium balls. It was really hard work but in the end I had one kilogram of powder. 

Here is some of the equipment I used to make my TOP SECRET mixture.

You might think this process sounds a bit strange but that is what is needed if I am going to take my material over to the University of Waikato to use a machine called an extruder. This machine will heat up my concoction and squeeze it into a mould. That mould creates a special test piece that can be tested for strength by being pushed and pulled apart. If it stands up to the test then we will have produced a material that is strong, free from faults and flexible enough.

One of the ways I could test the material I made was to look at it under the scanning electron microscope. I was looking to see how well the ingredients had mixed together. Below are some photographs of what I observed. You will notice purple boxes on the pictures. These were places where the microscope checked to see if all the ingredients were mixed together properly. The results were pretty good. Phew!

(LEFT) The secret mixture magnified 500 times and (RIGHT) 1000 times.

                                         
                         Experimental Extrusion Day 
Hello again. I now have some more to report on as I have returned from the University of Waikato where I got to test my experimental mixture in special machine called an Extruder. 

Students completing Engineering Degrees try out their concoctions on this Extruder.

After I was shown how to operate the machine safely and sensibly by Chris the Technician I begun by tested one of the six bags of my sample mixtures. Each bag had to be labelled and weighed so I knew what material it was and how much we were going to test. All our results were carefully recorded by Dr Peter and Dr Aamir checked the samples as they came out of the machine, whilst I ran the machine and made sure each of my mixtures were fed into the machine properly.  

Dr Peter is checking and recording and Dr Aamir is checking the extruded samples.

The material went into the Extruder as fine powder but once it was heated up it became like a gooey hot plastic and then it was pushed out in the form of a grey coloured toothpaste. The same way you squeeze toothpaste out of a tube in the morning when you clean your teeth. You do brush your teeth don't you?

Anyway! So we had a great day and learnt a lot about how to use the Extruder and run it in a way that worked for this special material. We also had some problems which we are now trying find answers for. We have had a few meetings to try to think of some possible solutions. 

I was very pleased that at the end of the day the machine had made some nice long sausages of metal about 15 centimeters in length. One day we hoped we could squeeze a material like this into a metal mould to make complicated shaped metal objects. 

Right now though we needed to test these samples. We are studying these under the Scanning Electron Microscope to see if the powder mixture we put in the machine and eventually came out as a hard metal sausage contains exactly the same amount of ingredients? Sometimes when you heat things up and squeeze them together at high pressures they can actually change and be different? We wanted to know that there had been no changes. I think we will need to go back again to do some more tests once we have solved some of the problems we had.....watch this space!

SEM and Material Testing for St Thomas More School.

Hi everyone, I am presently completing a small project for the school in preparation for an up and coming science topic. I have begun to analyse a series of materials using the scanning electron microscope. I had hoped to magnify the samples up to around 2000 times. 

Gold Plating 
However because the samples are not made of metal they do not produce clear images in the microscope with out receiving a fine coating of gold over the testing surface.This process is called sputtering and is done with a scientific instrument called Sputter Coating Machine. Once this was completed the samples were able to be analysed but could not be examined at such high magnification. 

Here is the holder with the samples.

Here are some of the fabric samples prepared for the Scanning Electron Microscope. It is hard to see the gold as it is a very fine layer only a few microns thick. These ones are all made from natural materials and the next samples I will analyse will be synthetic which means man made. 

Leather and Silk magnified 100 times. 

Here are a couple of photos of some natural fabrics and the two below are synthetic fabrics. There will be more to come in the form of a PowerPoint that will be sent to your teachers.

Carbon Fibre and Lycra at 100 times magnification.

Experimental Time at Waikato University.

http://sci.waikato.ac.nz/about-us/engineering

Click on the web address above and scroll down the page if you want to see a short movie made by a Bachelor of Engineering (Honours) student called Elizabeth Geddes who will show you around the School of Engineering's Large Scale Lab.

I am off to try my latest mixture of metal powder and plastic material at the University. I will be getting some help from a man called Paul who is an expert in this kind of scientific process. 

Here is a metal powder cookie and this is its surface viewed under the microscope.

We will be using the extruder again but he is also going to show me how to use a machine called a Granulator which will turn my metal and plastic cookies into pellets which will make it much easier for my mixture to pour into the extruder.

The last time we traveled to Waikato to use the equipment at the laboratory I had a problem getting the mixture to pour properly as it was too powdery. I have been experimenting with different ways (techniques) to grind up the cookies so I get little pellets rather than fine powder. Fine powder sticks together rather than flows easily and blocks up the funnel where the pellets pour into the extruder. My latest results are looking more promising. 

Here is the grinder I used to make the test granules that are in this plastic bag.

Unfortunately I need a lot more granules than 70 grams so I will need to use a much bigger grinder which is called a granulator. On the right are the bottles that hold the ingredients that make up my TOP SECRET recipe.

After all this work I am hoping the granules will fall into the heating part of the extruder, melt and be squeezed out of the other end of the machine through a small outlet called a nozzle. If I have worked out my mixture correctly the mixture should flow out in one long hot sausage. I have my finders crossed this will be the result. If it is I may be able to start the next stage of my investigation. This will be where I can use an injection moulder to make a metal object out of my metal powder recipe.

27-5-2015                      A Big Learning Day
I am relieved and pleased! It was a long day. A big thank you to Paul whose PhD expertise and experience made it possible to create a big tray of well formed MIM extrusions.    

Now I can make pellets out of my metal cookies by using the University's granulator. The finish product was excellent for its purpose and flowed easily into the extruder. This was a great relief after my last attempt several months ago which was a bit of a failure. 

Once we had created the pellets we tried them out using the extruder. Paul showed me that my first attempt at Waikato was unsuccessful because the temperatures I selected were far too hot. My lack of experience using the machine made it difficult for me to figure this out. I soon realised I had a lot to learn but now I know a lot more than last time. Once I got home I quickly recorded some of the things I had learnt. I have recorded some here on the photograph. I have learnt to take lots of photos as I work through my experiments. It is a great way to record details that you could forget without having the pictures to help you. The most important thing I have learnt from all this is NEVER GIVE UP and ask for help when you have done your best but you are still stuck!

                                 Time for Testing
Now that I have some extruded samples I can start doing some tests to see what is going on at a microscopic level. Without having the right scientific equipment this is not possible and so I am learning to do these tests when ever I create some new samples. Below are some photos of the testing stages. Sometimes this shows data that makes me ask some new questions? 

Injection Moulding

Now that we have created some good quality extrusions these will be cut up and fed into an injection moulding machine to see if they can create an object made of my metal cookie material. This is new stage of the experiment and will possibly bring new challenges and questions. 

I am learning that each science project is a journey of asking and answering questions. We try to answer these by using the evidence our testing has been able to find. This data then helps us understand what might be happening and we then talk about and think about possible solutions to solve the next challenge appearing on our scientific journey. This Blog page is trying to show my journey with the project I have been given by the scientists at TiDA.