Apple exploring nitride coatings for scratch-proof devices

Posted:
in General Discussion edited January 2014
Apple has shown interest in creating stainless steel electronic devices that are more durable and scratch resistant, thanks to a thin external coating of nitride.



This week, the U.S. Patent and Trademark Office published the details of Apple's invention in a new application entitled "Nitriding Stainless Steel for Consumer Electronic Products." It describes a cost-effective system that would place a layer of nitride atop a stainless steel exterior.



"In addition to providing a durable, hard surface that is both scratch and impact resistant, the nitride layer allows for the natural surface color and texture of the underlying stainless steel to remain visible to the user," the application reads. "It is this natural surface color and texture of the stainless steel that adds to the aesthetically pleasing appearance of the consumer electronic product, thereby enhancing the user's overall experience."



The ability of a nitride coating to allow the stainless steel color to show through is different from titanium nitride, a ceramic material also used as a coating on metal. Titanium nitride carries a metallic gold color that covers the metal beneath it.



Apple's proposed patent would maintain the look and feel of stainless steel on its electronic devices, by both allowing the color of the metal to show through the nitride coating, and also relying on the nitride to protect the device from scratches and blemishes.



The application notes that austenitic stainless steel, while scratch-prone, is a desirable material for consumer electronics because it is non-magnetic and less likely to inhibit wireless technology like a cell phone signal, Wi-Fi, or Bluetooth. Apple wishes to maintain the look and feel of stainless steel, but to also provide more protection for the external material.







Apple's patent application describes a variety of methods to place the nitride on the surface, where the material would be at least 15 microns thick and carry a Vickers Hardness value of at least 1,000.



The application, made public this week, is credited to Douglas Weber. It was originally filed by Apple on April 6, 2010.







Apple has repeatedly shown interest in making its devices more durable and protected from daily wear-and-tear. This August, the company entered into an exclusive agreement with Liquidmetal Technologies, creator of an amorphous metal alloy with unique atomic structures, allowing for products that are stronger, lighter, and resistant to wear and corrosion.
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Comments

  • Reply 1 of 38
    icarbonicarbon Posts: 196member
    When did Apple start having a chemical sciences division?
  • Reply 2 of 38
    envirogenvirog Posts: 188member
    Wow! Pretty cool tech for the shiny iDevices
  • Reply 3 of 38
    Quote:
    Originally Posted by AppleInsider View Post


    Apple has shown interest in creating stainless steel electronic devices that are more durable and scratch resistant, thanks to a thin external coating of nitride.



    This week, the U.S. Patent and Trademark Office published the details of Apple's invention in a new application entitled "Nitriding Stainless Steel for Consumer Electronic Products." It describes a cost-effective system that would place a layer of nitride atop a stainless steel exterior.



    "In addition to providing a durable, hard surface that is both scratch and impact resistant, the nitride layer allows for the natural surface color and texture of the underlying stainless steel to remain visible to the user," the application reads. "It is this natural surface color and texture of the stainless steel that adds to the aesthetically pleasing appearance of the consumer electronic product, thereby enhancing the user's overall experience."



    The ability of a nitride coating to allow the stainless steel color to show through is different from titanium nitride, a ceramic material also used as a coating on metal. Titanium nitride carries a metallic gold color that covers the metal beneath it.



    Apple's proposed patent would maintain the look and feel of stainless steel on its electronic devices, by both allowing the color of the metal to show through the nitride coating, and also relying on the nitride to protect the device from scratches and blemishes.



    The application notes that austenitic stainless steel, while scratch-prone, is a desirable material for consumer electronics because it is non-magnetic and less likely to inhibit wireless technology like a cell phone signal, Wi-Fi, or Bluetooth. Apple wishes to maintain the look and feel of stainless steel, but to also provide more protection for the external material.







    Apple's patent application describes a variety of methods to place the nitride on the surface, where the material would be at least 15 microns thick and carry a Vickers Hardness value of at least 1,000.



    The application, made public this week, is credited to Douglas Weber. It was originally filed by Apple on April 6, 2010.







    Apple has repeatedly shown interest in making its devices more durable and protected from daily wear-and-tear. This August, the company entered into an exclusive agreement with Liquidmetal Technologies, creator of an amorphous metal alloy with unique atomic structures, allowing for products that are stronger, lighter, and resistant to wear and corrosion.



    Will this be applied to the MBP line eventually?
  • Reply 4 of 38
    welshdogwelshdog Posts: 1,765member
    I know this isn't exactly the same, but the DeLorean comes to mind here. Sales of the car were not meeting expectations and one reason was that consumers had only one color choice - stainless. Researchers at DuPont (I think) came up with a paint for the car that apparently looked fantastic. It was transparent so you could see the stainless underneath. One problem. After about a year it would start peeling off the stainless substrate. They could not use it and not long after the car failed in the market place.



    This nitride coating is not the same as paint of course, but Apple should be very sure that it will behave as expected in the real world. I would be bad to have customers returning their devices after 6 months because the coating was flaking off.
  • Reply 5 of 38
    Quote:
    Originally Posted by WelshDog View Post


    This nitride coating is not the same as paint of course, but Apple should be very sure that it will behave as expected in the real world. I would be bad to have customers returning their devices after 6 months because the coating was flaking off.



    A variety of the Nanos have come in anodized colors, so Apple already has a good track history of testing and producing coatings. Nitriding the surface should (in theory) be even less of a risk, since it's colorless.



    Quote:
    Originally Posted by iCarbon View Post


    When did Apple start having a chemical sciences division?



    Does anyone have a 'dope-slap' smilie? Apple does more than just aesthetic design.
  • Reply 6 of 38
    Surely they're working on glare resistant glass screens as well, perhaps even transparent metal? Come on Jobs, invest a billion in transparent aluminum research, don't let a little money get in the way of making the world like star Trek.
  • Reply 7 of 38
    kibitzerkibitzer Posts: 1,114member
    The general coating process is called salt bath nitriding and in itself is not particularly new. I haven't seen the content of Apple's patent yet, but it's likely to embody one or more elements of four unique aspects. 1.) The composition of the substrate. 2.) The composition of the salt bath. 3.) The composition of the nitride mixed into the salt bath. 4.) Process methods, equipment, etc.
  • Reply 8 of 38
    Quote:
    Originally Posted by WelshDog View Post


    ... This nitride coating is not the same as paint of course, but Apple should be very sure that it will behave as expected in the real world. I would be bad to have customers returning their devices after 6 months because the coating was flaking off.



    Sounds to me like a coating for the antenna. The metal they currently use for the steel band is quite soft and could certainly use it.



    This is the same kind of coating they sometimes put on high speed drill bits so I'm sure it won't flake off later and although "1,000 on the Vickers Hardness scale" is kind of a meaningless thing to say, it seems like the implication is that it wold be something like five to ten times harder than steel.
  • Reply 9 of 38
    Quote:
    Originally Posted by frugality View Post


    Does anyone have a 'dope-slap' smilie?



    Perhaps this one comes close?



    Or better yet (sorry, couldn't resist):
  • Reply 10 of 38
    gctwnlgctwnl Posts: 278member
    The solution for the iPhone 4 antenna-shortcut problem?
  • Reply 11 of 38
    finetunesfinetunes Posts: 2,065member
    This would be ideally suitable for the iPod Touch since it has a stainless steel body. Might loose the shine though---IMHO would be better.
  • Reply 12 of 38
    Quote:
    Originally Posted by Kibitzer View Post


    The general coating process is called salt bath nitriding and in itself is not particularly new. I haven't seen the content of Apple's patent yet, but it's likely to embody one or more elements of four unique aspects. 1.) The composition of the substrate. 2.) The composition of the salt bath. 3.) The composition of the nitride mixed into the salt bath. 4.) Process methods, equipment, etc.



    Yup... nitriding stainless steel is nothing new in itself (http://en.wikipedia.org/wiki/Nitriding), and Titanium can also be nitrided - in any case, it is NOT a coating (not in its usual sense - think of it as a surface treatment).... the nitrogen bonds/diffuses at the surface layer of the metal and chemically changes/alloys the steel surface layer (increasing hardness and corrosion resistance of the surface while retaining the main steel bodies strength/elasticity).



    I've a titanium watch with a nitrided finish - first watch i've bought that wasn't scratched within hours of purchase - the nitriding is very effective.
  • Reply 13 of 38
    wizard69wizard69 Posts: 13,377member
    Quote:
    Originally Posted by BB Sting View Post


    Surely they're working on glare resistant glass screens as well, perhaps even transparent metal? Come on Jobs, invest a billion in transparent aluminum research, don't let a little money get in the way of making the world like star Trek.



    There is a lot of military research going into transparent "metals" for use as bullet proof windows. I quoted metals because the Aluminum isn't pure at all and can be likened to a ceramic.



    As far as glare resistant, almost everything available will impact image quality. Worst the coatings for glass might not be as durable as Apple would like. There is no easy answer especially after users get use to the quality of the glass screens.



    On a side note the screens in the new AIRs are interesting technology wise.
  • Reply 14 of 38
    wizard69wizard69 Posts: 13,377member
    Quote:
    Originally Posted by Kibitzer View Post


    The general coating process is called salt bath nitriding and in itself is not particularly new. I haven't seen the content of Apple's patent yet, but it's likely to embody one or more elements of four unique aspects. 1.) The composition of the substrate. 2.) The composition of the salt bath. 3.) The composition of the nitride mixed into the salt bath. 4.) Process methods, equipment, etc.



    I would not be surprised to find out they are using the same old nitriding techniques and simply patenting their use on consummer goods. Nitriding has been around for a very long time so the only thing I could see them having success with patenting would be a high volume process.
  • Reply 15 of 38
    i've always wondered why there isn't more work done with ceramics.



    they can be tough and they don't interfere with radio signals.
  • Reply 16 of 38
    ... from watching Cinema Paradiso?



    Oh wait - that was nitrate.



    Never mind.
  • Reply 17 of 38
    While nitriding will make the surface harder and more impact resistant, it also makes it more open to chemical attack as it essentially deposits reactive species on the surface of the metal.



    With this in mind, you're unlikely to see it being used on a product made by apple - i don't think they want devices that slowly turn black with age.
  • Reply 18 of 38
    kibitzerkibitzer Posts: 1,114member
    Quote:
    Originally Posted by Prof. Peabody View Post


    This is the same kind of coating they sometimes put on high speed drill bits so I'm sure it won't flake off later and although "1,000 on the Vickers Hardness scale" is kind of a meaningless thing to say, it seems like the implication is that it wold be something like five to ten times harder than steel.



    For sure, the coating is much harder than steel, but most hard coatings are brittle by themselves. Hard coatings have less tensile strength and malleability, which is why they're applied to a more durable substrate for the specific purpose of providing the surface scratch resistance. There's quite a lot of new metallurgical development going on in this area of late, particularly in the realm of powder metallurgy (PM) parts.
  • Reply 19 of 38
    cnocbuicnocbui Posts: 3,613member
    Quote:
    Originally Posted by fezzasus View Post


    While nitriding will make the surface harder and more impact resistant, it also makes it more open to chemical attack as it essentially deposits reactive species on the surface of the metal.



    With this in mind, you're unlikely to see it being used on a product made by apple - i don't think they want devices that slowly turn black with age.



    I have never seen a Titanium nitride coating on a cutting tool turn black or corrode in any way.
  • Reply 20 of 38
    My first use would be for the backs of iPods. As it is now a good sneeze creates a scratch.
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