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acorneau
Aug 23, 2013, 12:09 AM
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Just read this interesting article on how they're figuring out how to make a "stainless" (corrosion-resistant) magnesium alloy. http://www.sciencealert.com.au/...rt-Latest+Stories%29 Anyone with better know-how in the metals department want to comment on how this may eventually make its way into the climbing gear world? Come on magnesium cams!
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rocknice2
Aug 23, 2013, 2:00 AM
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Interesting article, at 1/3 the weight of aluminum. Add to that some carbon nanotube cables and cams can become lighter than some of today's quickdraws. I just wonder if when the cam tracks out of the crack, you may not only deck but also flash in the pan. A bright white light followed by a mushroom cloud of desert dust.
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JimTitt
Aug 23, 2013, 6:53 AM
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Well, itīs roughly 2/3rds the weight of aluminium not 1/3rd. And basically fairly weak in metal terms so useful for stuff used in compression but tensile itīs strength/weight ratio isnīt any better than aluminium alloys or steel alloys. A bit like titanium which many think is some wonder material but in reality the engineering benefits are less than one would hope for due to itīs weakness.
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rocknice2
Aug 23, 2013, 3:08 PM
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The article said
In reply to: Weighing in at two thirds less than aluminium, magnesium is the lightest structural metal. 1-2/3=1/3 ? But Jim is 100% correct it is 2/3 the weight of aluminum
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curt
Aug 23, 2013, 4:51 PM
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At first blush, arsenic doped magnesium doesn't sound all that attractive. Curt
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USnavy
Sep 3, 2013, 9:21 AM
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JimTitt wrote: A bit like titanium which many think is some wonder material but in reality the engineering benefits are less than one would hope for due to itīs weakness. Hua? Titanium alloys are very strong. Far stronger than 7075 AL. Grade 5 titanium has a UTS of around 138,000 PSI which is about as strong as a grade 7 medium-carbon-steel bolt.
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JimTitt
Sep 3, 2013, 5:45 PM
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USnavy wrote: JimTitt wrote: A bit like titanium which many think is some wonder material but in reality the engineering benefits are less than one would hope for due to itīs weakness. Hua? Titanium alloys are very strong. Far stronger than 7075 AL. Grade 5 titanium has a UTS of around 138,000 PSI which is about as strong as a grade 7 medium-carbon-steel bolt. Sure, and T5 is far heavier than 7075 so the strength/ weight gains are minimal (maybe 1-2%), and a decent steel alloy like 4340 can be over twice the strength of T5 but isnīt twice the weight. Divide the strength by the s.g. and;- 7075 = 29,537psi T5 = 31,151 4340= 36,607 Start looking at the lower Ti grades and things look even worse, T2 is easily outperformed by cheapo stainless for example.
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lemon_boy
Sep 3, 2013, 9:47 PM
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one of the common sayings in the manufacturing industry: "titanium - weaker than steel and heavier than aluminum, luckily it is a bitch to work with".
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JimTitt
Sep 4, 2013, 7:06 AM
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Yup, there are good reasons why out of all the climbing gear companies in the world nobody makes any Ti gear, itīs been tried for cams, karabiners pitons, ice screws, nuts etc and never worked. The expense of the material isnīt generally of any concern since most gear uses so little but loads of other factors make it a poor choice, where Ti does have advantages over other metals is in areas generally of no interest to climbers except for bolts where the weight is irrelevant and the weakness and price of the material is a considerable problem. The most common application for Ti in the outdoor industry is probably cooking gear which probably says more about the power of advertising than any real benefits since my cheapo aluminium pans work better than my Ti ones. Magnesium is similarly let down by itīs weakness and considerable difficulties in working and the future at least in the short term is probably aluminium composite forgings which seem to display most of the desirable features we need for much of our gear.
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USnavy
Sep 4, 2013, 8:50 AM
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JimTitt wrote: Yup, there are good reasons why out of all the climbing gear companies in the world nobody makes any Ti gear, itīs been tried for cams, karabiners pitons, ice screws, nuts etc and never worked. The expense of the material isnīt generally of any concern since most gear uses so little but loads of other factors make it a poor choice, where Ti does have advantages over other metals is in areas generally of no interest to climbers except for bolts where the weight is irrelevant and the weakness and price of the material is a considerable problem. The most common application for Ti in the outdoor industry is probably cooking gear which probably says more about the power of advertising than any real benefits since my cheapo aluminium pans work better than my Ti ones. Magnesium is similarly let down by itīs weakness and considerable difficulties in working and the future at least in the short term is probably aluminium composite forgings which seem to display most of the desirable features we need for much of our gear. Sure, I agree that titanium is not all that worthwhile in the climbing realm. But titanium does have one application in which it greatly excels. That is applications in which strength and weight are important, but corrosion-resistance is also very important. Most titanium alloys significantly outperform austenitic and even superaustenitic or duplex steels in terms of corrosion performance, but still retain a reasonable amount of strength and lightness. Titanium also seems to be one of the best if not the single best option for surgical implants due to biocompatability, low weight and high strength, and high corrosion resistance, as well as the fact that you can go in an MRI with a Ti pin but you cant use one with a 316L pin. But I agree, the Ti name is overinflated and the material is not too necessary that often.
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milesenoell
Sep 4, 2013, 3:44 PM
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USnavy wrote: JimTitt wrote: Yup, there are good reasons why out of all the climbing gear companies in the world nobody makes any Ti gear, itīs been tried for cams, karabiners pitons, ice screws, nuts etc and never worked. The expense of the material isnīt generally of any concern since most gear uses so little but loads of other factors make it a poor choice, where Ti does have advantages over other metals is in areas generally of no interest to climbers except for bolts where the weight is irrelevant and the weakness and price of the material is a considerable problem. The most common application for Ti in the outdoor industry is probably cooking gear which probably says more about the power of advertising than any real benefits since my cheapo aluminium pans work better than my Ti ones. Magnesium is similarly let down by itīs weakness and considerable difficulties in working and the future at least in the short term is probably aluminium composite forgings which seem to display most of the desirable features we need for much of our gear. Sure, I agree that titanium is not all that worthwhile in the climbing realm. But titanium does have one application in which it greatly excels. That is applications in which strength and weight are important, but corrosion-resistance is also very important. Most titanium alloys significantly outperform austenitic and even superaustenitic or duplex steels in terms of corrosion performance, but still retain a reasonable amount of strength and lightness. Titanium also seems to be one of the best if not the single best option for surgical implants due to biocompatability, low weight and high strength, and high corrosion resistance, as well as the fact that you can go in an MRI with a Ti pin but you cant use one with a 316L pin. But I agree, the Ti name is overinflated and the material is not too necessary that often. I'm dubious about your claims of titanium's superiority for surgical implants. As I had it explained to me, the primary considerations are brittleness and removability. Since steel is considerably less brittle it is the best choice for use in applications that are subjected to high strain. That was the rationale stated by my orthopedist for choosing steel for the two plates and a dozen screws in my ankle and foot. The other aspect is removability. Since Ti rapidly oxidizes with exposure to air, creating a microscopically textured surface (but does not corrode in the body) it encourages bone to attach to it, making it unsuitable for applications in which a piece may be removed. Since one big screw holding my ankle together while the joint healed was to be taken out later, again they chose steel because it's smooth surface does not encourage bone to to attach as readily as titanium.
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dynosore
Sep 4, 2013, 4:25 PM
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I can't see magnesium gear any time soon. Too weak. But in a real jam, you could scrape some shavings off with your knife and make a rescue flare maybe
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dynosore
Sep 4, 2013, 4:31 PM
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I'm a materials scientist, polymers to be exact, but I recently had an opportunity to examine some developmental phase metal superalloys a university wanted tested. Wow. These will be too expensive for climbing gear, but if the technology trickles down, expect big changes. Think the corrosion resistant of stainless steel, density less than steel, and ultra tough AND impact resistant.
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JimTitt
Sep 4, 2013, 7:59 PM
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milesenoell wrote: I'm dubious about your claims of titanium's superiority for surgical implants. As I had it explained to me, the primary considerations are brittleness and removability. Since steel is considerably less brittle it is the best choice for use in applications that are subjected to high strain. That was the rationale stated by my orthopedist for choosing steel for the two plates and a dozen screws in my ankle and foot. The other aspect is removability. Since Ti rapidly oxidizes with exposure to air, creating a microscopically textured surface (but does not corrode in the body) it encourages bone to attach to it, making it unsuitable for applications in which a piece may be removed. Since one big screw holding my ankle together while the joint healed was to be taken out later, again they chose steel because it's smooth surface does not encourage bone to to attach as readily as titanium. Well yes and but! Curiously enough my ex-climbing partner lives back in the states and is in the titanium surgical implant industry, and that is the essential point. Unlike screws and plates surgical implants are supposed to grow into the bone structure (or the other way round really) which is why titanium lattice structures are the future. Simple plate/screw systems are normally surgical steel/nickel alloys to allow removability. One of the fascinations (and frustrations) of engineering is looking at the huge number of materials available and the possibilities to use them but at the same time working within the limitations imposed. Most people just look at the simple numbers such as tensile strength or weight and forget there will probably be a downside somewhere. If you look at something like a cam one obvious place to save loads of weight would be in the swages, say by using titanium. But stainless is good because it work-hardens a lot so you can use a relatively strong but soft piece of stainless, crush it onto the wire and it hardens. If you replace it with titanium you need a bigger swage so the cam head becomes bulkier which isnīt what customers want or need. With bolts you end up in a similar situation compounded by manufacturing problems. Welding Ti is relatively expensive and not without problems so we have been working on some other designs. A 6mm (sorry, Iīm a Euro) material stainless bolt copes with anything a climber can throw at it but change over to grade 2 Ti and we can just get enough strength but the ductility (your surgeon was confused between shear strength and ductility by the way) and the lack of work hardening means the eye is still relatively soft and in normal use distorts alarmingly, so much so the product would be unusable. Instead you end up using 8mm which gives a material cost twice as high and proportionally vastly higher than the equivalent stainless bolt. Or you go to a higher grade Ti and while the material size drops the cost rockets up. Such is life!
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verticon
Sep 4, 2013, 8:05 PM
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Speaking of the future of gear, what about the "strong aluminium alloy, special hardening treatment" of the 19G Edelrid karabiner ? http://www.edelrid.de/en/sports/products/hardware/nineteen-g.html Is it a revolution or an engineering/marketing trick?
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gunkiemike
Oct 24, 2013, 10:25 PM
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verticon wrote: Speaking of the future of gear, what about the "strong aluminium alloy, special hardening treatment" of the 19G Edelrid karabiner ? http://www.edelrid.de/en/sports/products/hardware/nineteen-g.html Is it a revolution or an engineering/marketing trick? AKA anodized aluminum? Welcome to 1972...
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