CMG Technologies has produced a metal 3D printed model of the head of Kratos, the lead character in the God of War video game series.
The company produced a detailed model of the head as a keychain, and also delivered a slightly larger bust of the character as a Christmas gift for a lucky recipient.
The piece was produced using the Tech X 316L stainless steel filament on a 3DGence MP260 X metal FFF printer.
With sinter-based additive manufacturing technologies, prints must go through a de-binding process, to remove the binder from the part. CMG used acetone in the de-binding process for the Kratos print.
“It was de-bound in acetone, at 40 to 42 degrees, with a slow ramp up to avoid cracking during the de-binding process, we slowly ramped it up for about two hours,” Sam Wilberforce, R&D Head 3D Printing at CMG Technologies, told TCT. “With this de-binding process in acetone, it allows you to remove some of the acetone dissolvable binder components to create a natural extractor for effective sintering.”
After the Kratos print was de-bound in acetone, it had to go through sintering. The remaining backbone binder was removed at around 600 degrees, which made way for the sintering, which ocurred at around 1200 degrees. After this, the part was polished to get the desired surface finish.
Wilberforce told TCT about other applications the company created with the metal FFF 3D printing technology: “Some of the applications of our metal 3D printing technology include crimp jaws, bicycle ratchets and a dragon pendant.”
The crimp jaws, which are used to seal against the high internal pressure of electrical machines, were printed for a customer in CMG Tech X 17-4 PH stainless steel. This material was also used for the bicycle ratchets for another customer, as well as being utilised in roofing applications for a client in the automobile industry.
The dragon pendant (pictured above) used the same 316L stainless steel material that was harnessed for the Kratos print. Though printed as a gift, the Kratos print wasn't without its challenges.
“One of the challenges was the creation of an adequate support structure, which had to be removed in one piece for sintering,” Wilberforce said. “It had to be carefully removed so you have the part in one piece without breaking it. Another challenge was the de-binding step in acetone, ramping up slowly from 20, to 23, 26, 29 and slowly up to 40 degrees so that you don’t get cracking in the print.”