Creating parts using metal powders requires exceptional high-quality raw materials. Many analytical tools are used to pre-screen metal powders to ensure proper powder flowability, prevent clogging, and ensure adequate particle deposition to guarantee well-made parts. The additive manufacturing process is highly dependent on particle size and shape. Hence the value of dynamic image analysis for this growing industry.
Dynamic image analysis can be used to screen particles for both size and shape. It can be used to quantify any out-of-specification metal powders, helping users to differentiate between new, used, and bad particles in metal printing powders. If you intend to use metal powders for 3D printing, they must have the following criteria:
- High purity
- Good flowability
- Uniform particle size distribution
How Important is Metal Powder Particle Size and Shape?
For additive manufacturing, new powders are generally very uniform in size and very round in shape. This ensures the ideal flowability of raw metal powders as they are fed to the 3D printer for use. This also reduces the probability of voids on the parts that would cause the part to have weak points. Therefore, testing for size and shape is a common practice for manufacturers of metal powders for additive manufacturing and by the end users of these powders before making parts.
In many cases, there are times that left-over “spent” powders can be recollected and reused for subsequent parts. Here lies a point in the 3D printing process where it is even more critical to ensure the proper size and shape of these spent particles before reusing them. Although using spent powders offers an opportunity to save money and reduce waste, it also inserts a concern that some of these spent powders are no longer as spherical as the original virgin powders. In such cases, these “satellite” particles, where particles are stuck to each other, can reduce flowability, clog 3D printers and even offer weak deposition points in the final product being made.
To further complicate the issue, typically, the amount of inadequate, fused, or satellite particles in spent materials are very low in quantity, making it even more challenging to identify. In fact, for this application, only number-based techniques would have the resolution to identify such low quantities of rare, yet very problematic, particles.
With So Many Techniques, Why Choose Dynamic Image Analysis?
As mentioned above, for metal powders in additive manufacturing, one must ensure proper size to meet the requirements set forth by the 3D printer and the part being manufactured. With the added requirement of knowing the raw material feedstock must be very circular in shape, Dynamic Image Analysis now becomes an ideal tool for this quality control need. Dynamic Image Analysis, being a number-based technique, can identify and quantify very small amounts of out-of-specification particles. In addition to size, shape, and counting, Dynamic Image Analysis also offers the ability to detect and identify these troublesome particles
Real-Life Application Study
Vision Analytical had the opportunity to help a customer who manufactures parts with 3D printers using metal powders. Their goal was to see if Dynamic Image Analysis could do something that no other technique could do. They wanted to see if this technique could differentiate a virgin metal powder from one identified as slightly used (“spent”) but still adequate for printing without any clogging or deposition problems. And they also wanted to see if this technique could be used to identify a “bad” sample where the amount of satellite fused particles was too frequent and gave significant problems with their 3D printer and with the end product.
As this video will show, the Hydro Insight was able to not only differentiate the three samples based on size and shape, but was also able to quantify the number of out-of-spec particles and offer images to validate the identification of these bad particles.
Are you ready to use dynamic image analysis?
Size, Shape, Number, and pictures of bad particles in a sea of good particles makes Dynamic Image Analysis an ideal tool for metal powders in additive manufacturing.
If you want to learn more about how dynamic image analysis can help screen metal powders for 3D printing, then Vision Analytical is here to help you. Call 305-802-7240 or email Sales@ParticleShape.com today!
