DLC and the impact on blade tempers

[steelcity16]

I was inquiring about getting one of my fixed blades DLC coated and received an unexpected response from the maker. This got me thinking, is there any impact to the performance of Spyderco's DLC coated blades due to the high temperatures of the DLC coating process?

Perhaps Larrin or Sal could weigh in?


This is from my conversation over on another forum...

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Nathan, see Josh from REK's response to my question about DLC coating an FK2. Thoughts? Has anyone here DLC coated one of your knives?

"Yeah, I'm taking orders for a batch now... You would need to check with Nathan to make sure the temper would be fine, my DLC is applied at 500F."

Nathan's response...

"**** no. That's a problem. Stay away from my knives with those temps. Renders eta carbide useless, reducing cryo to just retained austinite conversion and little else."

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[JRinFL]

I had been assuming that it was a chemical bonding process without a significant heat component. I can see I was very wrong. I'm curious to see where this leads.

[steelcity16]

I had been assuming that it was a chemical bonding process without a significant heat component. I can see I was very wrong. I'm curious to see where this leads.

I am not sure if this is unique to Nathan's "Delta" 3V heat treat though as Josh stated that normal 3V tempering should be fine. Perhaps most standard production heat treats aren't affected by the temps. Or perhaps the DLC process Spyderco uses is lower temp (or chemical only as you said) compared to the service Josh at REK uses?

another response from Josh at REK...

"Hahaha, yeah I know normal 3v tempering temps are fine but I wasn't sure about the delta 3v. Guess that answers that question! Sorry about that!"

[kobold]

So, if different DLCs are applied at diff temps, what temp is used for Golden DLC?

[NarwhalisnotKosher]

Interesting.

[Cambertree]

It’s been mentioned here before that not all steels are suitable for DLC coatings, due to this issue, IIRC.

I’d like to see a reference for the claim about it adversely affecting eta carbides though.

[Xformer]

Yeah, that's something I'd like to know.

I've always avoided coated blade for the small particle that could get into your food. You never know. Still, I'm curious.

[Oloung1]

I've always avoided coated blade for the small particle that could get into your food. You never know. Still, I'm curious.

Couldn't this also be the case with satin finish or etch?

[Xformer]

I've always avoided coated blade for the small particle that could get into your food. You never know. Still, I'm curious.

Couldn't this also be the case with satin finish or etch?

I'm not an expert but Satin finish isn't adding lasting material on the steel, like coating is.

[James Y]

So, if different DLCs are applied at diff temps, what temp is used for Golden DLC?

I’ll hazard a guess that the temp used is proprietary information to Spyderco.

Jim

[Danke]

I would guess if DLC is rubbing off in what you're eating you have bigger problems.

Re DLC vs. heat treat I would suspect they build that into the post production instructions so it doesn't have a negative impact on the steel.

[ladybug93]

i just came here to say this thread title reads just like a science fair project. it would be the coolest science fair project ever though.

[Xformer]

i just came here to say this thread title reads just like a science fair project. it would be the coolest science fair project ever though.

Honestly ? You're right. Way too many unanswered question in the knife world. We should fund testing and researches. I still remember that glorious thread on bladeforum, the one about steel testing.

[applejuice54]

So this never got answered?

Like to know for M390 purchase decision with or w/o DLC would be good to know as m390 at 60 HRC is meh but at 62 it starts to kick some ***.
And since this is 2024 and Spyderco is bringing coatings in house be nice to know a little science.