The super alloy
The super alloy
“Iron is one of the most stable atoms as far as the nuclear structure is concerned. The energy levels found in the nuclei of Iron and other nearby elements suggest that they require a huge amount of energy to be disrupted. That is one part of the argument why the fission products end up nearby the atomic configuration of Iron.” Mr. Chenoy was in full flow today as he was explaining the fission reaction to the twelfth graders. The students maintained pin drop silence and that itself was measure of respect for their old teacher.
Mr. Chenoy was sixty-nine years old and it was amazing that he taught with the same enthusiasm as he did a few years ago. At five feet and eleven inches and seventy kilos, he was quite good as far as health for his age was concerned. His teaching career spanned more than twenty years and he was very respected in the community. He was awarded a fellowship of The Metallurgical Research Centre (MRC) after his successful and ground breaking demonstrative studies about super dense alloys, when he was only thirty and he never looked back since. He held several posts in various research programs across the country and intermittently he took metallurgy subject in schools for free. It just gave him immense satisfaction that way. He had a secret mission in his life, which was to generate, as much interest in metallurgy in India as he could, for according to him it was the basic science required to be looked into for any technology.
“Boys and girls!” He used to enjoy treating his pupils as kids, even if they were scientists or his colleagues. No body was complaining and it was just fine. His attitude towards the audience was of that of a very careful father and he never used to criticize them even if they did gross mistakes, be it exams or routine class questions.
Of late he had developed a theory about an Iron-Magnesium-Lead super dense alloy, which was nothing else than an extension of his thesis, which he had worked on almost thirty-nine years ago. All these years he had perfected the ‘art of alloying’, as he called it, during various trials of such alloys. A team of scientists at the MRC labs developed the alloy under his guidance and right now, it was being tested for repeatability of its performance parameters.
“Kids. Today, I am going to share a secret with you but you must promise that you will not speak about this to any body.” He spoke amidst a pin drop silence and the class got a bit noisy. “Shall I have your word then?”
“Can we know the topic first? Sir!” an eager question came from the crowd.
“Well. It is about a super secret Indian government project.” And the class was so silent that somebody must have thought that it was vacant. “Not even to your mothers, girls!” he said and all of the boys giggled as the girls looked in disbelief towards their teacher. “And you boys are no good either. Bragging before your friends!” and this time it were the girls who had a laugh. “Well then. Settled. I am going to tell you this because one of you had come to me yesterday and had asked about the real world applications of what we study within these four walls.” And everybody turned to face Nandan Bhat, the bespectacled boy who always asked minimum two questions per lecture. “No. No. No. It was not Nandan.” And every body looked at each other. Who dared to walk in the teacher’s room and ask him the most dangerous question that had not been answered since, maybe ages.
“I will not disclose the traitor” and again the air was filled with smiles, “but I will tell you the secret right away.” And every body was sitting on the edge of their seats.
“Do you have any idea what we are working on in the Metallurgical research Centre? Any guesses?” He asked.
“Super strong plastics,” said Nandan and every body gave him a funny look and anticipated a ‘yes’ from their teacher. But he said “No”
“Steel” said Kishore and everybody turned on to see who spoke and then to their teacher. “No” was his reply
“Nanotechnology” said Trupti and again “no”
“Computers” said Raman and again “no”
“Bio polymers” said Nandan and Mr. Gupta said “You were closer at you first attempt and Nandan got an admiring look from every one.
“World’s largest cheese burgers” said Hari and the class erupted in laughter, as did Mr. Gupta. “Nice try Hari. I think you had one today at lunch” and they laughed again.
“Flying saucers?” said Namrata and every body quickly turned to their teacher with a nod.
“OK. OK. I will tell now. We have developed a prototype alloy which has shown a density of 35.87 gm per cc.” And every body listened in silence but the fact seemed to have not much impact as their teacher expected.
“That means it is two times more dense than Lead” said Nandan and everybody turned their heads towards him.
“Quite Close Bhat. But, this number is the exact number, which you can get if we take two dense metals and mix together. It is homework for all of you. Find the closest combination of metals that will add up in density to this number.” And every body took it down word by word in their writing pads.
“Sir! But I would like to ask one thing. What is the use of such heavy metal? Yesterday only we studied that the weight to strength ratio is important and we are constantly searching for lighter and still stronger materials.” And nobody had to guess who would dare to ask this question. It was Nandan. Everybody was now looking at Mr. Chenoy for his reply.
“Kids. Before answering this question, I would ask you to enumerate, one by one, the use of lead in our life.” Said Mr. Chenoy and several hands were seen in air.
“Yes, We will start with Kruti.” He said and up came the reply “Sir. Medals are made up of lead” and every body was laughing.
“Well. I think you got one gold plated lead medal last year for swimming isn’t it dear?” asked Mr. Chenoy.
“Yes and the coat has started to peel off showing me the lead base,” she said and the tone of disappointment was clearly felt by every one.
“But, take heart from the fact that in most of the tournaments the medals have a lead based alloy within. Now Shashi, what is your say?” he said.
“Sir. Solder alloys” and everybody turned his or her head to admire that answer. “Correct. Some solders use lead. Divya?” Said Mr. Chenoy.
“Poisons” and everybody jerked for this was the most interesting answer anybody could expect.
“Very correct but, it is used as a compound.” Mr. Chenoy said. “Bharat?”
“Lead acetate paper” he said and Mr. Chenoy said “Hmm. Compound again. Chemistry seems to be more popular than Physics here it seems. Come on people, I want a use in Physics now.” Mr. Chenoy said and students began to discuss.
Nandan had opened his physics notes and was frantically searching for something and so were many of them. His hand shot up in the air after sometime. Every body fell silent and waited for Mr. Chenoy to call him.
“Yes, Nandan” he said
“Shielding material for radiation. Sir” and every body joined him with an approving nods and Hums. “Good. Right on target”
“Why is it used as a shielding material?” asked Mr. Chenoy and every body was thinking hard.
“Does it have anything to do with the density of lead?” asked Nandan.
“Well, very correct. Anybody interested in knowing how?” asked Mr. Chenoy to an eager audience.
“Yes sir.” Came the reply
“Well, the more dense the element is, the more close are the atoms placed in the crystal structure to each other. And, imagine millions of balls thrown on to a three-dimensional net with nodes as atoms. The finer is the net hole, the lesser is number of balls, which would pass through it. Now, replace the balls with the neutrons or photons and the net with a solid crystal. So, the denser metals will stop the particles mores than the less dense elements. Get it?” Mr. Chenoy had drawn a figure on the black board as he spoke.
The students nodded as some of them copied the diagram in their books.
“The nature has given us many dense elements.” Mr. Chenoy spoke further “Uranium is one such element that is used some times instead of lead in some very specific areas but, then the issue of radiation comes up. The Uranium is radioactive.”
“So, we tried to develop an alloy using the two very stable elements as far as radioactivity point of view is concerned, lead, which is the end product of natural radio-decay of many radioactive elements and Iron, as explained earlier, with the most stable nuclear configuration.”
“Did you really make it?” asked up a tensed up Hari.
“Well, as far as prototype is concerned, we are right now stocking seventy six grams of it.” Said Mr. Chenoy as the class gasped.
“And it has the density of 35.87 gm/cc? But, isn’t it a scientific breakthrough? Somebody can win a Nobel here ” said Kruti.
“Well. Nobel is a far-fetched possibility but the alloy is in such a constrained environment that it is practically not utilizable at the moment. And the Nobel is awarded to those who make something, which can be practically utilized. Let us forget the Nobel for now. But, can anybody now tell me why more and more dense material will be useful?” Asked Mr. Chenoy to the, now very interested, students.
“Sir, does this mean that we need lesser material for shields?” said Nandan.
“Well, you can say that. But, think a bit more technically. The mass may not change. OK. It is homework for all of you to search as much information on this matter. And, do not open your mouths anywhere about whatever I told to you. We have not even published the results of our experiments in our Science journals. Meet you tomorrow with the homework complete. And, if you guess what technique we used to create such a super alloy, I give you a treat. ” Said Mr. Chenoy as he left the class.
Next day, all students came with all the preparation. Nandan was spotted with some very thick books titled ‘Berkeley Physics Course’ and ‘Metals and Alloys’ and of course no other student had seen these before. He had got these from his father’s college library. Kruti was sporting a ‘Metallurgy and Alloying science’. Hari’s friends caught him in the lunch break reading a magazine titled ‘Frontiers in Metallurgy’ and they lost all hope of finishing their leftover cricket game from yesterday’s break. The whole class seemed to enjoy decoding the puzzle given to them by their teacher. A treat was at stake. And the interesting thing was that last time their teacher had given Nandan a treat, it was no food or fun, it was a cool 1000x microscope with backlight for clearer viewing. But that was for scoring cent percent in five out of seven subjects in his eleventh class half yearly exams. This time they expected something like that only. One other time he had given a treat, Kishore had got a fabulous scientific information CD for achieving a great result in class tenth exams.
There was an anxious stir when Mr. Chenoy entered the class for the fourth period. And as he entered, he started where he had left the day before. He asked, “So, Let us start guessing. The best guess gets this cool book on metallurgy titled ‘super alloys’ released this week from Oxford University press. It contains VITAL, and I mean VITAL, information on some of the strongest, difficult, specialty alloys” and every body was looking at the book in awe. The guesses started.
“Powder metallurgical process” told Kruti.
“Can you please elaborate it for your friends?” Asked Mr. Chenoy
“Sir. The lead and iron can be powdered in to micrometer diameter granules and then mixed together in right proportions and then heated under pressure to melt them and get an alloy,” Kruti read from her notes.
“Good knowledge addition but, the theoretical density that has been achieved till now with such processes never exceeds that of the original elements.” Said Mr. Chenoy and the class looked for some other hands in air.
“Electro-fusion under very high pressure!” shot out Nandan.
“Please elaborate,” said Mr. Chenoy, “You see what we are trying to do here? We are applying our scientific knowledge to create something new.”
“Sir. Under very high pressure such as one GigaPascal or so, we can heat the mixed elements using electricity for alloying.” Said Nandan
“Well, it seems similar to Kruti’s method. OK. We do it for some alloys where we require phase stabilization and other complications are there. But not here, the density will not increase to such an extent.”
“Vaporization and re crystallization” told Kishore.
“Are you sure? Mostly this technique is used for separation of elements based on density and temperature variation between them. Of course I would like to know how you could use it here?” said Mr. Chenoy.
“Sir, we can create metal vapors and then allow them to crystallize to form a single crystal. God knows if it will be denser than the original.” Said Kishore.
“Well, you are thinking one thing correctly though. We have to make a crystalline complex between these two metals. But your technique is far too power intensive and we have never done experiments to see if the alloy will be denser. Primitive instinct will say that the density will be the in between the higher and the lower one. But, kids, this is the major technique to separate some elements. Tomorrow you find out for which. This is homework number one. Next.”
“Attaining Plasma state and then Re crystallization” said Hari.
“Plasma state is a kind of nuclear gas and to get back the elements from such a mix up is very difficult. But your idea is close to what we used. Good try. Come on, I gave you a hint.” Said Mr. Chenoy and there was a buzz in the class.
“Implosion under heavy magnetic field” told Namrata.
“Very close indeed. Good. The implosion part is correct. But magnetic field does not fit in. How would you use it if lead were not magnetic? Any explanation?”
“Sir, the iron atoms can be frozen at their place using a very strong magnetic field and the lead can be imploded with it to get mixed and we have our alloy”
“Very good indeed. You know, kids! The research goes exactly the same way you here found out answers of a complex problem. We make a committee and try to figure out the most practical way to achieve the goal. The goals come out of the past experience. Let us say, a few years ago, we had radio waves transmitting sound. And, then, somebody came out with the idea of developing the cordless phone, which is based on a similar technique. Then, came the idea that why not send data in the digital form as it was on the computers. And thus came the era of wireless communication. So, we see that the inventions, discoveries come out of need of mankind to improve our lifestyle. But, we need basic science for that. So, I think I have answered your question Devashish?” Spoke Mr. Chenoy and everyone were looking incredulously at Devashish, who was a newcomer. He was very quiet and introvert usually and he had popped out the dreaded question.
“But, Sir! Can we know the technique you used to create the super alloy?” This time all the students gave a gasp as they heard Devashish speak. It was like a voice from the deep seas, so clear and yet unheard of.
“Yes! But, you should promise that you would not tell any body.” Mr. Chenoy spoke as he wiped his spectacles with his handkerchief.
“We do sir” came a coherent reply.
“We used the implosion technique with lasers and fused iron and lead to get very small quantities of the alloy. The implosion was carried out in a similar fashion as some scientists are planning to create immense temperatures, about ten million degrees, of course for fusion reactors. The temperatures we achieved were about fifty thousand degrees. This brought the atoms closer than the crystalline structure and when solidified, we tried to measure the density and n the average of twenty six experiments, we have concluded that the remnant alloy is denser than the original elements. In some samples, the density goes up to 36 gm per cc. But, the implosion blows away most of the material. We got only a few milligrams of it. It is very costly, you know.” Mr. Chenoy spoke and waited for a few moments for his words to sink in.
“Now, that you are a secret keeper of our nation, you must promise that you will study science for fun and enjoyment and not as a burden! And Namrata gets a treat, which means she gets this book. She guessed most of the answer right. Claps for her,” said Mr. Chenoy and he handed over the book to Namrata and every body looked admiringly at Namrata as she blushed and others clapped.
The students hurriedly opened their science books and started studying for their exams next week as Mr. Chenoy was walking past them and answering one or two queries, as they were raised.