Patented Metals with Extremely High Carbide Content

Metal materials with remarkable properties. This has been the focus of Swedish company VBN Components since the very start. In the middle of the financial crisis in 2008, VBN saw the opportunity to turn the steel business upside down by using additive manufacturing of high strength, carbide-rich materials. Today they present a range of patented alloys with unique performance.

The Vibenite® materials

VBN Components nurtures the Swedish heritage within the metal industry by continuously developing new and improved materials branded Vibenite®. Sweden was one of the first countries in the world to produce industrial steel with purity as a key factor. VBN takes this to the next level by 3D printing materials unique in their composition, offering exceptional wear resistance. Their properties are achieved by a patented additive manufacturing process through which metal materials with 100% density can be produced. Small sized uniformly distributed carbides in a specific matrix are the reason for the materials’ performance. They are all produced from a base of gas atomized metal powder and are therefore classified as powder metallurgy materials.

Vibenite® technology allows the user to switch to a more wear resistant material than what can be produced with traditional manufacturing. When 3D printing, most production and transportation steps are eliminated, material usage optimized, and environmental impact significantly reduced. Both performance and life-time of components increase with Vibenite®. These properties are easily tested by simply printing a full-quality prototype and running it! Better material properties are normally not heard of in the 3D printing business today, where typically difficult geometries are promoted.

Your application of choice can be printed with Vibenite® materials.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cross section of shaper cutter showing a 100% dense material.

 

 

 

 

 

 

 

 

 

 

 

 

 

Caption: Hardness of Vibenite® materials compared to H13, a common tool steel.

Vibenite® 290, the world’s hardest steel

Today there are five different types of Vibenite® materials, with a hardness range from 58-72 HRC (600-1100 HV). Among them we find the world’s hardest steel, Vibenite® 290 with 25% carbide content. Its hardness of 72 HRC means it could never be processed traditionally. It was recently put through two abrasion tests to measure wear against rock, in collaboration with Robit Plc. The results spoke for themselves; Vibenite® 290 showed only 50% of the wear rate compared to reference material H500 (51 HRC) in the first test, and 25% of the wear rate in the second. H500 is commonly used in these types of abrasion lab-tests.

Total wear in grams in high-speed slurry pot test.

 

 

 

 

 

 

 

 

 

 

 

 

 

Vibenite® 480 – a new type of cemented carbide

Recently, VBN Components announced that they can print cemented carbide. This type of material has previously been considered “impossible” to print, due to high carbide content. Vibenite® 480 contains an astonishing ~65% of carbides, which really beats al the odds. There is no mixing, drying, pressing or sintering needed, as in the traditional process. It has a long-term heat resistance of 750°C, is corrosion resistant and magnetic. Vibenite® 480 is niched both towards applications where steel is normally used, but where replacing it with hard metal would increase production efficiency, and also towards hard metal applications with complex geometry. Since it combines the best of two material worlds – powder metallurgy high-speed steel and cemented carbide, it is referred to as “hybrid carbide”.

3D Benchy printed with Vibenite® 480.

 

Milestones and future projects

These material innovations have raised quite a lot of attention. Already in 2013, VBN Components was awarded with Sweden’s largest and most important innovation prize, SKAPA, established in honor of Alfred Nobel. In that same year, Swedish steel giant Uddeholms AB contested VBN’s first patent regarding high purity in high carbon content materials. It took five years before the battle was finally settled, in favor of VBN Components, at the European Patent Office (EPO) in Munich. Not long thereafter, just before Christmas of 2018, a multi-million license agreement was signed with a global engineering group. It implies an exclusive license within a specific niche of high-strength components, which is kept confidential for now.

VBN Components is the only company 3D printing alloys with high carbon content, resulting in hard and wear resistant unique materials. The extremely high cleanliness of Vibenite® alloys gives very high fatigue resistance. Following this path, VBN will continue developing new metal alloys and novel ways to print these. The possibilities are vast, from “Vibenite® Combo” which implies printing Vibenite® upon other existing components, to “Vibenite® Grado” which would give different properties in different parts of the component.

How Argon and Nitrogen Shielding Gases Affect 3D Printed Stainless Steel

The micro-hardness results of specimens fabricated in Argon and Nitrogen L-PBF atmospheres for the as-built and heat-treated conditions

 

In a paper entitled “Mechanical Properties of 17-4 PH Stainless Steel Additively Manufactured under Ar and N2 Shielding Gas,” a group of researchers investigates the effect on using either argon or nitrogen as the shielding gas on the final mechanical properties of additively manufactured 17-4 PH stainless steel.

“Many efforts have been done to optimize or improve the mechanical properties of AM parts by investigating various process parameters, scan strategies and building orientation effects,” the researchers state. “Shielding gas has been introduced as another significant parameter which affects not only the thermo-physical but also the mechanical properties of fabricated parts.The shielding gas is responsible for the removal of reactive gases surrounding the melt pool to prevent detrimental effects of reaction with atmospheric gases like oxygen. Various factors such as the base material and chemical-metallurgical reactions of the gas with the melt pool must be considered for choosing the appropriate shielding gas.”

Effects of various shielding gases such as nitrogen, argon and helium have been studied on the behaviors of different materials such as carbon steels, stainless steels and aluminum alloys. The researchers focus in this study on “modeling the thermal response of 17-4 PH SS by simulating a single track during typical L-PBF conditions while considering convection heat transfer for different shielding gases.”

A numerical study was performed to obtain the temperature, temperature gradient and cooling rates of parts fabricated under argon and nitrogen shielding gases during laser powder bed fusion. Micro-hardness testing and tensile tests were carried out to determine the mechanical performance of the 3D printed parts under the different shielding gases. The following conclusions were reached:

  • The nitrogen atmosphere introduces slightly lower temperatures and temperature gradients along tracks while the cooling rate is higher than that of the argon atmosphere. The researchers attribute this to the higher thermal conductivity of nitrogen gas.
  • More energy should dissipate from the track to the environment when nitrogen is used as the shielding gas. This is due to the higher cooling rate provided when using nitrogen gas.
  • The hardness of specimens fabricated under nitrogen shielding gas is slightly higher than the fabricated specimens under argon gas. This is attributed to the finer microstructure obtained due to the higher cooling rates provided while under the nitrogen atmosphere.
  • “The HT-Ar/Ar specimens have higher hardness than HT-Ar/N2 ones. This is due to the higher capability of precipitation hardening in the martensitic microstructure compared to the austenitic matrix as a result of fabricating under Argon atmosphere.”
  • There is minimal variation in tensile behavior under all of the tested conditions. However, the specimens 3D printed under the nitrogen atmosphere have slightly higher strength and ductility.

This research may provide valuable insight into how better to avoid defects in additively manufactured parts, such as porosity and lack of fusion. Metal additive manufacturing in particular is a very precise science that involves a great deal of chemical knowledge and mathematical calculations in order to create the optimal conditions for 3D printing. Based on the researchers’ study, manufacturers may be able to alter the conditions under which they 3D print parts, allowing for better overall final components.

Authors of the paper include Pooriya Dastranjy Nezhadfar, Mohammad Masoomi, Scott Thompson, Nam Pham and Nima Shamsaei.

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GE Additive Customer Uses DMLM 3D Printing to Manufacture Blades for Medical Cutting Device

endoCupcut

As the population continues to age, the number of necessary hip replacements rise, which means we’re seeing more 3D printed hip implants and hip cups. Implanting a hip cup is fairly straightforward these days, but removing one, for reasons ranging from abrasion and infection to loosening, is another story. Surgeons typically have to use a hammer and chisel for this, which can damage tissue and bone and make it hard to reinsert a new implant.

Germany medical device company Endocon, a GE Additive customer, is using additive manufacturing to make it easier for surgeons to remove hip replacement cups. The company isn’t 3D printing the cups, but instead created a new device, called an acetabular cut cutter, with 3D printed blades. This product has improved not only the surgical experience for the patient and physician, but the cost savings and product reliability as well.

“We’ve also been able to reduce the cost per blade by around forty to forty-five percent. That means cost savings for us and in turn for our customers,” said Klaus Notarbartolo, the General Manager at Endocon. “When you combine that with a reduction in product development time, higher efficiency and lower rejection rates, then the business case for additive really becomes attractive.”

Typically, traditional casting is used to manufacture cutting blades, but for an end product that comes in a variety of shapes and sizes, it could take up to three and a half months to produce a single batch of blades. Casted blades can also have a rejection rate of about 30% due to issues like non-repeatable quality, corrosion, and consistent hardness.

The company called on GE Additive’s Concept Laser Mlab Cusing 100R, which uses direct metal laser melting (DMLM) technology, to 3D print the blades for its endoCupcut in 17-4 PH stainless steel. This reusable device allows surgeons to quickly loosen and extract cementless hip cups without damaging the surrounding bone, as its blades allow for more precise cutting along the edge of the acetabular cup. Additionally, it can be combined with up to 15 different 3D printed stainless steel blades in sizes ranging from 44 mm to 72 mm, and makes it possible to implant the same size cup that was originally there.

The 3D printed blades for the endoCupcut, which had only minimal changes from the original model, can be available in just three weeks, including post-processing. The device now has a rejection rate of less than 3%, can achieve consistent outcomes, and the 3D printed blades show excellent corrosion resistance. Rather than cracking after 600 N, the blades show a plastic deformation after applying 1,8 kN, and their hardness level has improved to 42+-2 HRC, compared to 32 HRC.

“Endocon’s ability to solve multiple challenges using additive is impressive example of how it can have a positive impact for smaller companies targeting the orthopedic industry,” said Stephan Zeidler, Business Development Manager Medical for GE Additive. “What started with the need for a reduced time-to-market in terms of product development and flexible production of various shapes and sizes has resulted in a smart, innovative medical product that enhances patient outcomes.

“Moving the entire production process from casting to additive manufacturing was a logical step and that shift continues to provide inspiration for future projects.”

Metal 3D printing specialist and service bureau Weber-KP manages the entire process, including data preparation, build platform orientation, 3D printing, surface finishing, hardening, and bead blasting, for Endocon. The company has even improved the manufacturing process of the blades in order to, as GE Additive put it, “maximize the best possible outcome” and can fit between two and six blades on the Mlab Cusing 100R’s build platform, depending on orientation and size.

Using DMLM technology to 3D print the blades has improved their mechanical properties, and also ensures high density and accuracy. By using stronger, harder, and more reliable blades on the endoCupcut, the device performs better for the surgeon in the operating room, and also makes things safer for the patient by lowering the risk of breakage and splinters being embedded in their tissue. Using this device, surgery time has been decreased from 30 minutes to just three, and its precise cutting method preserves the highest possible amount of bone substance, which “supports an accelerated healing process for the patient.”

Other benefits of fabricating the endoCupcut blades with DMLM 3D printing include:

  • High-fitting accuracy of blades through modular system of ball-shaped heads
  • Perfect fitting of ball-shaped heads in a 38-60 mm width
  • Reusable for multiple operations
  • Wear-resistant and easy to sterilize

Lowering surgical risk saves hospitals money and time, and the world is definitely taking notice of Endocon’s innovative work. The endoCupcut is already being used by several medical professionals around Germany, and the company itself is a finalist in the TCT Awards next week.

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[Images provided by GE Additive]