How was adamantium bonded with Wolverine’s skeleton? Surface coating, or was the metal infused into the bone?

Question

A scene in X-Men '97 where Gambit charges Wolverine's adamantium claws with his powers got me thinking: How exactly was the adamantium integrated with Wolverine’s skeletal structure (which I believe includes his claws)? (I'm curious if Gambit’s power affected only the adamantium or if it extended to the bone structure of Wolverine’s claws as well.)

Was the adamantium more of a surface coating or plating, keeping the metal and bone distinct? Or was the adamantium actually infused, injected, or permeated into the bone tissue itself, so that the bone is now one with the adamantium?

I'm mostly interested in the comic book Wolverine — Earth-616, to be specific. However, insights into the different iterations of Wolverine or other characters who underwent a similar adamantium-bone bonding procedure would also be appreciated.

Answer 1

In the six-issue story arc Weapon-X from Marvel Comics Presents #72–84 (1991), we get to see the whole process in all its gruesome details.

Wolverine was captured for the Weapon-X program led by Dr. Abraham Cornelius. He was sedated, and tubes of liquid adamantium were fed into his skeleton.

After the process, Dr. Cornelius evaluated the results and found them a complete success.

The result was described as a perfect synthesis of human trabecular and adamantium.

Trabecular bone is the internal tissue of the bones in the skeleton and is usually quite porous. Somehow, the process made the adamantium bond to this material, making the bones indestructible from the inside out.

Furthermore, in the X-Men animated series, Season 2, Episode 5, they show Wolverine's origin. The process is less violent here but is shown in some detail. They call the process "bonding," and Professor Cornelius explains to Wolverine afterwards that his bones have been fused to adamantium. We also see a glimpse of the adamantium being absorbed into the bones, changing them from the inside.

This also shows that the bones are fused completely to the adamantium and not just coated.

Answer 2

According to his profile on Marvel.com:

Wolverine’s skeleton is encased in adamantium, including his lethal retractable claws.

They also say that his healing power:

allowed Doctor Cornelius and his team to fuse adamantium to his skeleton.

and

very bone in his body is covered in an unbreakable material.

It's worth pointing out that in Fatal Attractions, Magneto strips the adamantium from Wolverine's bones. In a flashback, we later learn that the adamantium is rebonded to his skeleton by Apocalypse.

Answer 3

I always assumed they replaced his entire skeleton with a metallic one, otherwise some of his his bones would break.