Metals

I was wondering if you guys could answer a few questions for me.

What metal causes the least amount of friction?
What is the most durable metal?
What metal works best when moving fast and colliding together with other metals?
What metal is the smoothest?
What metal is the lightest?
What metal is the easiest to mill and cut but still durable?

The help and answers are greatly appreciated.

Tags:

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

-Least ammount of friction I would personally say are the various types of cast iron. Graphite precipitates within the metal, and acts as lubrication to reduce friction (cast iron brake rotors or drums on cars are plain old cast iron because of this)

-The lightest metal is Lithium, though its worthless as a metal. Beryllium is second, and finds many applications. In other words, Lithium is the lightest; Be and Mg are the lightest usefull metals.

-smoothness has everything to do with how polished the surface is, not necessarily a material property.

-define "durable". Toughest? Highest Tensile strength? High modulus of elasticity? Tool steels are often used for "durability" applications such as drill bits, connecting rods on cars or other various internal components, gun barrels etc just to name a few.

-There are to numerous to mention alloys that mill easily, and still possess high strength after they have been appropriatly tempered/quenched/age hardened/nitrided/carborized.............. Examples are Aluminum, which is typically milled to shape then age hardened to bring out the high strength. Or the Pb-steels. Most metals go through some sort of strengthing treatment after they are milled/shaped, so in other words, the before properties are drastically different than after properties. We want to be able to shape the metal easily (cheaper tools, bits etc), then give the proper treatment to gain the necessary hardness/strength properties.

There are just so many different metals/alloys that its hard to definitly say "this is the answer to your question". Alot of the metals possess better properties than steels or other popular alloys, however cost factors in

[quote="scarf"]
-define "durable". Toughest? Highest Tensile strength? High modulus of elasticity? Tool steels are often used for "durability" applications such as drill bits, connecting rods on cars or other various internal components, gun barrels etc just to name a few. [/quote]
Toughest.

You see, I am looking to build a paintball gun and I need something that can shoot at a high velocity. I also need something durable, light and smooth. I need an all around good metal that is rather cheap and easy to find. Nothing majorlly expensive.

Now after saying that, what do you think would be the best metal for my sitution?

I really appreciate the help. :D

Titanium

In the words of Mike Nicols: Plastics!

A paint ball gun is essentially an air gun; you can make the thing out of PVC tubing and it will work; metallic properties such as tensile strength, ductility, annealing traits, and malleability are largely irrelevant. Since the paint ball is basically a gelatin capsule, you just need a substance that is stronger than gelatin.

You need to know mechanical stresses, fatigue analysis etc for something like that. Then given the properties, you could then pick out the appropriate materials. I would say make it out of "aluminum", but aluminum has thousands of different alloys, all of which need to be treated differently. Some of the internal parts would probably need to be steel, as aluminum is fairly weak and ductile in comparison. I would keep the non-aluminum parts to a minimum, as no one wants to carry around a 20 pound gun.

Well, everything will be an alloy...you don't want a pure element for a use such as paintballing...anything and everything will react with it =P

obviously he wouldn't use a pure metal. The only pure elemental metal use I know of is in X-ray tubes, though there are probably other specialty apps I'm unfamilar with. If you want a break down of the possibilties to consider for any strength application here goes a short list-

steel - heavy
aluminum - light easy to work with, difficult to weld
titanium - light, pain to work with, extremely difficult to join, $$$$$$$$
magnesium - super light, $$$$$$, difficult to work with, brittle
Brass/Bronze - heavy, possible galvanic corrosion
Zinc - brittle, easily cast, very cheap
carbon fiber - super light, expensive, fabrication difficult

Take your pick. I pick aluminum, because the gun will be just as light, and signifcantly cheaper than a Ti gun. I might put a Ti barrel on it, but only because I don't want to shoot sliders ("spinners" for you UK - cricket people) out of a bent barrel cause you fell on your gun.

WebElements: the periodic table on the WWW [http://www.webelements.com/]

Copyright 1993-20010 Mark Winter [The University of Sheffield and WebElements Ltd, UK]. All rights reserved.