Case Study of Using Particle Image Analysis Device Morphologi 4 and Powder Rheometer FT4: Interview with Professor Yanagitani from the University of Hyogo

We conducted an interview with Professor Yanagitani from the Industry-University Collaboration and Research Promotion Organization, Center for Metallic Materials Research at the University of Hyogo. The Center for Metallic Materials Research has introduced the Particle Image Analysis Device Morphologi 4 and the Powder Rheometer FT4. In this article, we discussed the research content that the professor is currently conducting, how they utilize the devices, and the activities of the Hyogo Metal Belt Consortium.

We asked about the research content that Professor Yanagitani is currently conducting.

In 3D printing technology, the laser powder bed fusion method is frequently used. I am studying the metal powder materials used in this method. Almost all materials used in laser powder bed fusion are based on gas atomized powder, which is the mainstream. The reason why gas atomized materials are adopted in laser powder beds is that they are spherical with good flowability. Additionally, they have a proven record of being used for various applications other than 3D printing. As a result, 3D printing manufacturers used gas atomized materials as the standard when developing printer devices.

However, materials produced by the water atomization method can be made more cheaply than those by the gas atomization method. This is because water atomized powder has been used in the sintering field for a long time and has good productivity. I thought it would be important for 3D printers to spread in the future that the materials used are inexpensive.

Coincidentally, upon examining Epson Atmix’s powder, I found it to be a beautifully spherical powder, similar to gas atomization. I thought this could be useful for 3D printing. When compared to the currently used gas atomized powder materials, I noticed that Epson Atmix’s powder is very similar. So, I thought it might work for 3D printing, and when I used it for the laser powder bed, it worked well! This is where it all began.

Upon investigation, it seems that water atomized materials are mainly produced for use in MIM (metal powder injection molding) and are aimed at processing raw materials into spheres to produce products with excellent surface properties. As a consequence, they can also be used in laser powder beds.

We were shown a fabrication using water atomized powder. It is an example of a planetary gear where six gears revolve while rotating, and it is a feature of 3D fabrication that starts from the beginning of the fabrication without incorporating the gears later, ensuring they do not come off.

How are Malvern Panalytical’s devices being used in relation to your research?

I previously had the opportunity to use the Morphologi 4 Particle Image Analysis Device. At that time, knowing that it could measure particle shape, I wanted to use it. When adopting the water atomization method materials, it was necessary to view the shape of the particles in images, and thus, we adopted the Morphologi 4.

Moreover, through the activities of the Hyogo Metal Belt Consortium, the necessity to measure the physical properties of other powder materials arose. For instance, there are materials produced by plasma melting. This method allows for the creation of composite materials of metals and ceramics, and compared to other methods, it can achieve a nearly spherical shape. Therefore, detailed particle shape information such as sphericity is required, which necessitates measurement with Morphologi.

Additionally, the reason I considered using the Powder Rheometer FT4 was to evaluate the flowability of water atomized powder. Water atomized powder generally has smaller particle size and worse flowability compared to gas atomized powder and cannot be evaluated by JIS standard flowability tests. FT4 allows quantitative measurement of shear force and viscosity resistance, and is used for flowability evaluation. I think this is a strength of this device. We utilize FT4 to verify the level of flowability. It was immediately requested by companies involved in the consortium research to be used post-introduction.

Please share your thoughts on actually using our devices.

Frankly speaking, devices like Morphologi 4, which use image analysis methods, gave me the impression that they took a long time to measure in the past. Especially compared to laser diffraction methods, it felt like the measurement time was longer. However, with the advancement of computer processing capabilities recently, the measurement time has been significantly shortened, which surprised me. Additionally, being an application of microscopy, the operation is quite intuitive. A wealth of measurement data is obtained, allowing for detailed image analysis, which I think is very well-suited for activities in this consortium. There are also companies that requested to use this device as soon as it was introduced. Moreover, what is most important is that it requires a small amount of powder to conduct measurements. It’s a relief to save valuable materials as it only needs a small amount approximately the size of a spatula for measurement.

For materials used in the laser powder bed, information on flowability and powder shape is important. As FT4 allows quantitative understanding of flowability, a wide range of analyses is possible. FT4 is a device with its own unique parameters, and powder data can be obtained for comparison with others. This means you can confirm the data relatively. Thanks to FT4, we believe we can also obtain data regarding the surface characteristics of particles. The powder particle shape data measured with Morphologi 4 and the data measured with FT4 can be related, making both devices very interesting to utilize. Part of the research results obtained using this equipment will be presented at World PM2024 (Yokohama). We will also introduce research results at the joint display booth of the Hyogo Metal Belt Consortium at formnext2024 (Frankfurt) in November.

Could you tell us about the future research contents and the activities of the Hyogo Metal Belt Consortium?

I intend to continue research on the water atomization method in the laser powder bed system. Also, the activities of this consortium began with the approach that, rather than dealing only with molding, research should start from the powders when advancing research at the university. Currently, we are conducting research on various materials such as gas atomization, water atomization, and plasma melting methods.

For example, in the plasma melting method, it is possible to produce composite materials. We have received consultations from persons at companies dealing with plasma melting method materials, and we sometimes conduct 3D printing using new powders. In the future, it will likely become necessary to investigate the properties of such new materials, such as circularity and flowability.

It is important to explore unprecedented alloy compositions in this research institute and understand their properties. I believe this will lead to widening various possibilities.

About the Hyogo Metal Belt Consortium

Along the Seto Inland Sea coast, there is an accumulation of one of the nation’s leading metallic material manufacturing and processing technologies, forming the “Hyogo Metal Belt.” To enhance the added value of such industries, the “Center for Metallic Materials Research” has been established as a base for research and development of materials.
Here, we aim to establish and promote metal powder and 3D fabrication technologies that excel in hardness, heat resistance, and micro-machinability, required for next-generation industries. In particular, to support small and medium enterprises that are proactively introducing and utilizing metal 3D printers, we are engaged in technical support through industry-academic collaboration with companies possessing advanced technologies.
The consortium offers technical consultation, management consultation, joint research, seminars, and workshops for its members, and also holds a “seeds-needs matching” presentation, which is very well-received by companies as a platform for PR and learning about the technologies of other companies. Even members who do not have offices in Hyogo Prefecture can join and participate, so please feel free to contact us if you are interested.

Hyogo Metal Belt Consortium Website

Contact: kinzoku@eng.u-hyogo.ac.jp

Interviewee Details

Hyogo Metal Consortium
The University of Hyogo, Center for Metallic Materials Research
Vice Director, Specially Appointed Professor
Professor Akihiko Yanagitani

Profile
Joined Sanyo Special Steel Co., Ltd. in 1981 and involved in the launch of the metal powder business. In 2018, became a specially appointed professor at the University of Hyogo, and in 2019, a visiting professor at Osaka University. Engaged in research, product development, and practical application of metal powders. Served as a director of TRAFAM from 2016 to 2021. Launched the Hyogo Metal Belt Consortium in 2019 and currently serves as the Vice Director of the Center for Metallic Materials Research, University of Hyogo, and Vice-chairman of the Consortium, focusing on research, development, and promotion of metal 3D layered fabrication. Secretary of the 3D Metal Additive Manufacturing Committee of the Japan Society of Powder Technology from 2020. Recipient of the Technical Award from the Japan Institute of Metals and Materials in 2010 and the Technical Achievement Award from the Japan Society of Powder Technology in 2022, among others.