INTRODUCTION

Author: Ben Arnold

Metal AM 2.0 promises a new era of affordable, high volume Additive Manufacturing (AM) of metal components. “Metal Binder Jet” technology is widely promoted by several  industrial powerhouses as THE technology that will usher in a new era of growth in the coming years.

However, this core technology has been around for 30+ years and faces some significant challenges that make it a bad fit for many applications and factories.

What’s the big deal? Does the paste make that big a difference? This white paper will help you understand exactly how a paste based feedstock addresses several key challenges facing binder jet adoption. We will share an overview of the MoldJet technology and some test results demonstrating the potential impact of this technology.

But first, some background.

WHY METAL AM?

Metal AM is an important technical advancement that offers several advantages over traditional manufacturing methods for producing metal parts. These advantages include:

1. DESIGN FLEXIBILITY

With Metal AM, it is possible to create complex geometries and internal structures that are not possible using traditional manufacturing techniques. This can result in lighter, stronger, and more efficient parts.

2. COST EFFICIENCY

Metal AM can be more cost-effective for small production runs or for producing parts with complex geometries that would be difficult or expensive to machine or tool up for casting.

3. TIME EFFICIENCY

Metal AM can reduce lead times for producing parts, as the technology allows for rapid prototyping and fast production of parts.

4. MATERIAL EFFICIENCY

Metal AM can reduce lead times for producing parts, as the technology allows for rapid prototyping and fast production of parts.

5. SUSTAINABILITY

Metal AM reduces waste and environmental impact by using less raw material, producing less scrap, and reducing energy consumption compared to traditional manufacturing processes.

METAL AM 1.0 – LPBF

Over the past few decades metal AM applications and markets have grown dramatically, mostly driven by the Laser Powder Bed Fusion (LPBF) process. With this technique a high-powered laser is used to weld metal powder particles together, layer-by-layer, to build up a three-dimensional (3D) metal part. This “direct” metal fabrication process is widely used in industries such as aerospace, medical, and energy where the production of complex, high-value parts is required.

While this process has been proven with many commercial successes, the technology is just too slow and expensive for most industrial applications. LPBF is also limited to materials that are weldable.

METAL AM 2.0 – THE RISE OF SINTER BASED SOLUTIONS

Sinter-based approaches widen the appeal of Metal AM by dramatically improving process economics. In recent years this sector, driven primarily by the metal Binder Jet process has received significant investment and market attention. Several large industrial players have committed substantial resources to develop and industrialize the process.

These efforts are all in the pursuit of lower production costs and faster time to market. This is achieved by using the forming process to manufacture “Green Parts”.  Green parts are metal powder that is “glued” together with special binders into the desired shape. Hundreds or even thousands of green parts can then be sintered  simultaneously in a furnace to generate solid metal parts. Cost advantages of 10X and more when compared to laser-based processes are common.

The Binder Jet process is promising, however there are fundamental physics challenges that may not be solved. A brief overview of the Binder Jet process and key challenges is presented below.

When reviewing these challenges, it seems clear that an entirely new method to achieve the promise of sinter-based metal AM should be considered. That is the path chosen by the Tritone team as they invented the MoldJet process.

SINTERING

One commonality between Binder Jet and MoldJet is that both processes manufacture green parts which are then sintered to reach their final form as solid metal parts. A few comments are relevant to the balance of this paper:

1. Sintering of powder metal “green parts” is a mature industrial process that has been implemented at scale for decades by Metal Injection Molding (MIM) and other manufacturing technologies. Billions of dollars of sintered metal parts have been produced annually – long before additive manufacturing.
2. When green parts are sintered, they shrink as the powder particles fuse together.
3. The sintering / shrinking process has been proven to produce extremely consistent results – IF the parts entering the sintering furnace are consistent.
4. Green parts that are DENSER going into the sintering furnace shrink LESS and hold better tolerances. MoldJet parts shrink around 14% while Binder Jet parts shrink 20% or more. That is 30% less shrink.

To continue reading, please click here to download the full White Paper.