## Materials Science C

Avogadro
Member
Posts: 66
Joined: January 6th, 2017, 4:51 pm
Division: Grad
State: PA
Location: Swarthmore College

### Re: Materials Science C

Hey guys, have you encountered any instances in which you had to calculate creep rate? I am finding some more complex equations that all involve calculus that are above the level usually included in Science Olympiad.
Yes, several times, though generally using given data points. Plot it to find the linear region (secondary creep), and your standard delta y over delta x usually suffices. I have yet to see a scenario involving calculus.
Thank you so much! So do Materials Scientists generally not care about the primary and tertiary creep? Or rather, for Science Olympiad purposes
For Science Olympiad purposes I haven't been too concerned about it. I'm sure it's more important if you're actually an engineer.
Lower Merion 2017
Subtitled: Revenge of the Non-Harriton

Placement Record:

Code: Islip | Conestoga | Tiger | Regionals | States
Out of: 61 | 42 | 36 | 37 | 36

Chemistry Lab: 9 | - | - | 4 | 4
Astronomy: 14 | - | 5 | 10 | 3
Material Science: 12 | 19 | 9 | 5 | 9
Optics: 14 | 7 | 3 | 4 | 2

hearthstone224
Member
Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

Question on closed packed planes coming at you guys if you don't mind. This comes straight off a practice test and is as follows:

Give the Miller indices of a family of close packed planes in copper. Use the conventional notation indicating a family of planes.

The answer is {1,1,1},

1. What is a close packed plane?
2. Where is this plane (isn't it just from 0,0,0 to 1,1,1 the plane that is formed there?)
3. Why is the answer {1,1,1}? How do you just know that?

Ok Thanks for the help.
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

hearthstone224
Member
Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

So I've looked it up and apparently there was something called slip all along, with specific planes that are easier to slip (which I think basically means to break/plastically deform easier on) on and these planes are along the close packed planes. {1,1,1} seemed to be the first one they said. Should I memorize these planes? There really isn't a way to "derive" them, is there? Like you just have to know them?
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

younessnb
Member
Posts: 1
Joined: March 11th, 2017, 11:23 am

### Crystal Structure

Hello everyone! I'm hoping to see if anyone can help me figure out how to determine the crystal structure that will be formed or a given material There have been questions on the practice tests that ask us to figure out the crystal structure of materials such as sodium chloride and I am not too sure how to figure that out without memorizing the structures of the materials. Thank you so much for your time!

hearthstone224
Member
Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Crystal Structure

Hello everyone! I'm hoping to see if anyone can help me figure out how to determine the crystal structure that will be formed or a given material There have been questions on the practice tests that ask us to figure out the crystal structure of materials such as sodium chloride and I am not too sure how to figure that out without memorizing the structures of the materials. Thank you so much for your time!
Something that might help would be the wiki, which kind of helps to explain the 6:6 ratio coordination between Na and Cl. Basically it means you have sodium atoms surrounded with 6 other atoms.

I'm really not quite sure though, I think there is something related with the atomic radii, and then you actually take a ratio between them and then you can figure out how it is coordinated... Maybe someone else can help. Hope this helps, though.
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

hearthstone224
Member
Posts: 132
Joined: October 13th, 2016, 1:50 pm
Division: C
State: IL

### Re: Materials Science C

I'd just like to thank everyone for their help. Freshman season officially over.

Got SECOND at regionals out of 12 teams for Materials Science (Only team that beat us was Stevenson which is a nationally ranked team) and so I'm very proud. I'll still be on the forums once in a while but probably won't be too dedicated anymore..

Just like to say thanks to everyone, and best of luck to all you guys out there! I really made myself a competitor and it showed today at the regional. Thanks and have a good one!
End of freshman season. Good luck to everyone! No state for us, but nevertheless great season. Regional was out of 12 teams. (CLC)

Mat Sci-> Second at regionals
RSensing -> First at regionals
Towers-> Third at regionals.

Tesel
Exalted Member
Posts: 161
Joined: January 30th, 2016, 8:03 pm
Division: C
State: MI

### Re: Materials Science C

Just had my regionals test this weekend, got 1st place!
Thanks for everyone who helped me figure out atomic packing, that section may have been the difference.
I was just boggled by one question... it showed a graph about reflection angle and intensity, and asked the spacing between certain atomic planes? If anyone understands what this is, I am very confused, and I'm not even sure if that's within the limits of the event.
University of Michigan Science Olympiad Div. C Event Lead

2018 MI Mission Possible State Champions

kaziscioly
Member
Posts: 27
Joined: August 28th, 2015, 6:10 pm
Division: C
State: IL

### Re: Materials Science C

Does anyone have any experience/advice about making cubic crystal models? We had to do something like this at our regional where we were given toothpicks, styrofoam balls, and beads to make a model of an FCC crystal, and that was a frustrating experience.

Avogadro
Member
Posts: 66
Joined: January 6th, 2017, 4:51 pm
Division: Grad
State: PA
Location: Swarthmore College

### Re: Materials Science C

Does anyone have any experience/advice about making cubic crystal models? We had to do something like this at our regional where we were given toothpicks, styrofoam balls, and beads to make a model of an FCC crystal, and that was a frustrating experience.
Yeah, I did exactly the same thing at Stoga and it made me want to rip my hair out. My best advice is to just 100% impale the things and get as many connections going as you can. If you're limited to only getting a certain number of styrofoam balls/toothpicks (like I was at Stoga) you need to be careful about how you impale the things, making sure you leave enough room to attach the other stuff to it. If you're not, I'd say to just go to town until you put together a working model.

tl;dr models are a crapshoot based on quality and quantity of materials given, from my experience.
Lower Merion 2017
Subtitled: Revenge of the Non-Harriton

Placement Record:

Code: Islip | Conestoga | Tiger | Regionals | States
Out of: 61 | 42 | 36 | 37 | 36

Chemistry Lab: 9 | - | - | 4 | 4
Astronomy: 14 | - | 5 | 10 | 3
Material Science: 12 | 19 | 9 | 5 | 9
Optics: 14 | 7 | 3 | 4 | 2

Tesel
Exalted Member
Posts: 161
Joined: January 30th, 2016, 8:03 pm
Division: C
State: MI

### Re: Materials Science C

Does anyone have any experience/advice about making cubic crystal models? We had to do something like this at our regional where we were given toothpicks, styrofoam balls, and beads to make a model of an FCC crystal, and that was a frustrating experience.
Yeah, I did exactly the same thing at Stoga and it made me want to rip my hair out. My best advice is to just 100% impale the things and get as many connections going as you can. If you're limited to only getting a certain number of styrofoam balls/toothpicks (like I was at Stoga) you need to be careful about how you impale the things, making sure you leave enough room to attach the other stuff to it. If you're not, I'd say to just go to town until you put together a working model.

tl;dr models are a crapshoot based on quality and quantity of materials given, from my experience.
Approximately how many of each were you given? I could see this being a good lab, but if materials were limited, that wouldn't really be in the spirit of the event.
University of Michigan Science Olympiad Div. C Event Lead

2018 MI Mission Possible State Champions

Return to “2017 Lab Events”

### Who is online

Users browsing this forum: No registered users and 1 guest