Apple granted invention of scratch-proof nitride metal device coating
Apple has been granted ownership of an invention related to scratch-proof coatings on stainless steel devices, using a nitride layer to potentially make iPhones, iPads and Macs more durable.
The U.S. Patent and Trademark Office this week granted ownership of the invention "Nitriding Stainless Steel for Consumer Electronic Products" to Apple. Known as U.S. Patent No. 7896981, it describes a cost-effective system that uses a nitride coating to prevent scratches and blemishes on the metal surface of a mobile device.
Adding a layer of nitride atop a stainless steel exterior would protect a device from damage. But the choice of material would maintain the look and feel of stainless steel, as nitride allows the color of the metal to show through.
Nitride is not to be confused with titanium nitride, a ceramic material that is also used as a coating on metal. Unlike nitride, which is clear, titanium nitride has a metallic gold color that conceals the look of the metal beneath it.
Apple's invention notes that stainless steel, while scratch-prone, is an ideal material to craft electronic devices. Stainless steel is preferable because it is not magnetic, and it is less likely to inhibit wireless technology like a cell phone signal, Wi-Fi or Bluetooth.
The addition of nitride could give Apple the best of both worlds: the advantages of stainless steel would remain, while a nitride coating would address the chief concern of durability.
The invention also includes specifics on how the nitride coating would be applied to a device. It describes using a salt bath nitride process to coat stainless steel with an initial layer at least 15 to 30 microns thick and with a Vickers Hardness value of at least 1,000. Another method would use a nitrogen salt bath with an average temperature of no more than 580 degrees Celsius.
After the stainless steel sits in a superheated salt bath for between 45 and 90 minutes, the material would be removed and the nitride layer would be polished to remove no more than 10 percent, resulting in a smooth exterior.
Apple first filed for the invention in April of 2010. It was discovered last October by AppleInsider, when the filing was made public by the USPTO. The invention is credited to Douglas Weber.
The U.S. Patent and Trademark Office this week granted ownership of the invention "Nitriding Stainless Steel for Consumer Electronic Products" to Apple. Known as U.S. Patent No. 7896981, it describes a cost-effective system that uses a nitride coating to prevent scratches and blemishes on the metal surface of a mobile device.
Adding a layer of nitride atop a stainless steel exterior would protect a device from damage. But the choice of material would maintain the look and feel of stainless steel, as nitride allows the color of the metal to show through.
Nitride is not to be confused with titanium nitride, a ceramic material that is also used as a coating on metal. Unlike nitride, which is clear, titanium nitride has a metallic gold color that conceals the look of the metal beneath it.
Apple's invention notes that stainless steel, while scratch-prone, is an ideal material to craft electronic devices. Stainless steel is preferable because it is not magnetic, and it is less likely to inhibit wireless technology like a cell phone signal, Wi-Fi or Bluetooth.
The addition of nitride could give Apple the best of both worlds: the advantages of stainless steel would remain, while a nitride coating would address the chief concern of durability.
The invention also includes specifics on how the nitride coating would be applied to a device. It describes using a salt bath nitride process to coat stainless steel with an initial layer at least 15 to 30 microns thick and with a Vickers Hardness value of at least 1,000. Another method would use a nitrogen salt bath with an average temperature of no more than 580 degrees Celsius.
After the stainless steel sits in a superheated salt bath for between 45 and 90 minutes, the material would be removed and the nitride layer would be polished to remove no more than 10 percent, resulting in a smooth exterior.
Apple first filed for the invention in April of 2010. It was discovered last October by AppleInsider, when the filing was made public by the USPTO. The invention is credited to Douglas Weber.
Comments
Scratch RESISTANT, not scratch PROOF!
So even though the patent was only just granted, would Apple have already begun using this on their products? My current aluminum MacBook and my original iPhone, as well as my wife's iMac all seem to be very scratch/blemish resistant. Is it possible thay have already been using this, or are their aluminum products just now going to be even more scratch proof than they already were?
I doubt they are already using it. This will probably be introduced into their new iPod line this fall and possibly into the iPad 2 (whose material we are uncertain about).
Scratch RESISTANT, not scratch PROOF!
Scratch RESISTANT, not scratch PROOF!
Actually...
it describes a cost-effective system that uses a nitride coating to prevent scratches and blemishes on the metal surface of a mobile device.
Key word there being "prevent" not reduce. True, it may not be completely preventable, but it may be nigh scratch-proof.
...Stainless steel is preferable because it is not magnetic...
Er... Yes, it is.
Er... Yes, it is.
\tfrom: http://www.physlink.com/education/askexperts/ae546.cfm
\tQuestion
Is stainless steel magnetic? Does it depend on the amount of chromium, or nickel alloy?
Asked by: James McGuigan
Answer
Stainless steels are a very broad group of metals. The name was adopted as a generic term for steel alloys with a minimum of 10.5% chromium. The chromium gives the steel its 'stainless' properties - essentially corrosion resistance. On the surface of the metal, a very thin chromium-rich oxide layer is formed which is inert - i.e. it prevents the steel from rusting. The advantage of stainless steels over plated steels is that, if scratched or damaged, the steel will 'self-repair' as a new oxide layer is formed. In plated steels, scratches in the plate will often lead to corrosion of the steel underneath.
In general, the higher the proportion of chromium, the stronger the corrosion resistance of the steel. In addition to chromium, other metals are added to give the steel particular properties such as strength and malleability. Specifically nickel is used to strengthen the oxide layer.
As for whether they are magnetic, the answer is that it depends. There are several families of stainless steels with different physical properties. A basic stainless steel has a 'ferritic' structure and is magnetic. These are formed from the addition of chromium and can be hardened through the addition of carbon (making them 'martensitic') and are often used in cutlery. However, the most common stainless steels are 'austenitic' - these have a higher chromium content and nickel is also added. It is the nickel which modifies the physical structure of the steel and makes it non-magnetic.
So the answer is yes, the magnetic properties of stainless steel are very dependent on the elements added into the alloy, and specifically the addition of nickel can change the structure from magnetic to non-magnetic.
The following company website has a useful high-level definition of the broad stainless steel categories. http://www.parkrow.org/stainless_steel.htm
You'd want a lot of baths / baths able to take many units. 90 would only give you 1 unit per minute, 1440 a day, 10,080 a week (given a 24hr production line) for 524,000 a year.
If you roll out 25mil iPads, not including other product lines that is 4300 ish baths going flat out not including moving units in and out or refreshing said baths.
That is also a lot of material and energy to consider. The volumes are enormous.
I'm not saying impossible or anything. I just find the volume of materials being processed and the logistics really interesting.
90min for each casing in a bath.
You'd want a lot of baths / baths able to take many units. 90 would only give you 1 unit per minute, 1440 a day, 10,080 a week (given a 24hr production line) for 524,000 a year.
If you roll out 25mil iPads, not including other product lines that is 4300 ish baths going flat out not including moving units in and out or refreshing said baths.
That is also a lot of material and energy to consider. The volumes are enormous.
I'm not saying impossible or anything. I just find the volume of materials being processed and the logistics really interesting.
Hmmm, so maybe that "data center" in North Carolina is really just full of bathtubs.
Wi we see a stainless ipad, MacBook pro, or iPhone? Who knows. But bring on the innovation, it only makes Apple stand out of the crowd.
90min for each casing in a bath.
You'd want a lot of baths / baths able to take many units. 90 would only give you 1 unit per minute, 1440 a day, 10,080 a week (given a 24hr production line) for 524,000 a year.
If you roll out 25mil iPads, not including other product lines that is 4300 ish baths going flat out not including moving units in and out or refreshing said baths.
That is also a lot of material and energy to consider. The volumes are enormous.
I'm not saying impossible or anything. I just find the volume of materials being processed and the logistics really interesting.
So you imagine an industrial scale assembly line giving each unit a private bath, one at a time? more likely it would either be 100 (or more) dipped into a large bath all at the same time - or a continuous ride through a bath for 90 seconds - with one unit entering every second on the front end and another emerging every second at the back end for 1 unit every 1 second through the bath = 60 a minute = 3600 an hour = 86,400 a day = 604,800 a week = over 30 million a year.
Stainless steel is generally brittle but I guess for a phone or computer it would be ok.
Brittle, huh? Guess all those automakers out there putting stainless steel exhausts on cars (and that's just about all of them), better watch out....
Brittle, huh? Guess all those automakers out there putting stainless steel exhausts on cars (and that's just about all of them), better watch out....
Exhaust systems are generally not under any load or stress. Stainless steel is also great for high heat applications but not so great in applications that involve lateral loads as anyone that has ever broke the tip off a knife will tell you. In a static object that will not get dropped from very high or twisted under any torque like a phone or laptop stainless steel will probably be fine.
90min for each casing in a bath.
You'd want a lot of baths / baths able to take many units. 90 would only give you 1 unit per minute, 1440 a day, 10,080 a week (given a 24hr production line) for 524,000 a year.
If you roll out 25mil iPads, not including other product lines that is 4300 ish baths going flat out not including moving units in and out or refreshing said baths.
That is also a lot of material and energy to consider. The volumes are enormous.
I'm not saying impossible or anything. I just find the volume of materials being processed and the logistics really interesting.
You don't have to dip just one casing in the bath at the same time, my friend.
Exhaust systems are generally not under any load or stress. Stainless steel is also great for high heat applications but not so great in applications that involve lateral loads as anyone that has ever broke the tip off a knife will tell you. ...
The first mistake in that case was to buy a stainless steel knife, the second to use it as a pry bar.
Yea yea, all very interesting
But know something that's impossible to penetrate
My ex's thick skull
.
(and hope it never gets patented)
.
Yea yea, all very interesting
But know something that's impossible to penetrate
My ex's thick skull
.
(and hope it never gets patented)
Thats only cuz you're not the sharpest tool in the shed