Apple's special gold isn't so special after all | Cult of Mac

Apple’s special gold isn’t so special after all


The gold in Apple's 18-karat watch is a standard gold alloy, not a miraculous gold/ceramic mix. Credit: Apple

All week, it’s been reported that Apple is using a “new gold” in the gold Apple Watch Edition. According to Bloomberg, Slate, Gizmodo and many others, Apple has patented a new process to create a “metal matrix composite” by mixing gold with ceramic particles.

The composite supposedly allows Apple to save on the amount of gold it uses, while making the substance super-hard and adding other amazing properties.

But according to Atakan Peker, a materials scientist and one of the co-inventors of Liquidmetal, which Apple holds an exclusive license on, it’s extremely unlikely Apple is using any kind of “new gold” for its watches.

He knows this because Jony Ive says so.

In the video above, produced by Apple to highlight its gold process, Ive explains how the watch body is made. He describes quite clearly that the gold is an alloy of silver, copper and palladium, not a composite.

Ive then describes how the alloy is cast into ingots, rolled and formed into billets, and machined to form the Apple Watch Edition’s case, buckle and Digital Crown.

The process makes no mention of ceramics, composites or any non-standard techniques. “There is nothing particularly new here,” said Peker. “These are known methods of production for gold parts.”

Peker is familiar with creating new metallurgic processes. As a graduate student at the California Institute of Technology in 1993, Peker co-invented Liquidmetal alloys with engineering professor Bill Johnson. Liquidmetal alloys have an atomic structure that is more like glass than metal. They are super-strong, scratch-proof, corrosion-resistant, extremely flexible and very light. They have been used for golf clubs, tennis rackets, skis, watches and cellphones.

Apple holds an exclusive license to use Liquidmetal in consumer electronics, but the company’s plans for the substance remain unknown. So far, Apple used Liquidmetal to make the SIM card ejector tool that shipped with early iPhones, but doesn’t appear to have used it since.

If Apple was using any kind of new gold for the Apple Watch, Ive’s video would show a very different process. It would show the cases being made from a composite material, not an alloy.

An alloy is created by melting different metals together (as shown in Ive’s video). The composite in Apple’s patent is created by mixing powders of gold and ceramic together, sintering and then heating them. The materials are bonded but don’t mix. By definition, a composite is a material made of distinct parts.

In fact, Peker said it’s unlikely that Apple’s composite gold will ever be used to make a watch.

“It is a smart idea,” he said, “but it will not make into a jewelry-quality watch case. Combining very soft with very hard ceramic particles is a nightmare for cosmetics and finish. It is almost impossible to get jewelry-quality polish and finish.”

In addition, the patented composite would feel very light. It “will not be perceived as genuine gold,” he said. “One attribute of gold is the feeling of being heavy. When you make it very light, people will not take it as genuine gold.”

Sara Shaughnessy, a jewelry designer with RedStart Design in San Francisco, and a Stanford mechanical engineering postgrad, agreed that the ceramic/gold composite wouldn’t be good for a watch.

“For jewelry, it would be a very limiting material,” she said. “You definitely won’t be able to treat it like a normal 18-karat gold.”

Shaughnessy said the material couldn’t be melted, cast, soldered or formed. It would have to pressed into its given shape and then polished. “And even the polishing might be different then normal gold with its unusual hardness,” she said.

“It’s a material best used in very specific applications,” she added.

Watchmaking probably isn’t one of them.


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