Production method of 17-4PH stainless steel powder for selective laser melting forming

Production method of 17-4PH stainless steel powder for selective laser melting forming

Introduction

With the rapid development of manufacturing industry, selective laser melting forming technology has been widely used as a high precision, high efficiency and strong flexibility manufacturing technology. In selective laser melting forming, the selection and production of material powder has become an important link.

17-4PH stainless steel is a popular choice for selected laser melting forming materials due to its excellent corrosion resistance, strength and machinability. The selection and production of 17-4PH stainless steel powder will be discussed in this article.

The chemical composition of 17-4PH stainless steel mainly includes Cr, Ni, Cu and other elements, and in the heat treatment process, its structure and performance can be adjusted by controlling temperature and time. Therefore, it has good formability and plasticity.

Production methods of 17-4PH stainless steel powder

The powder production method of 17-4PH stainless steel can be used by inert gas atomization, mechanical ball milling and chemical reduction. The production method of the powder has an important influence on the subsequent selective laser melting forming effect and the properties of the finished product.

Inert gas atomization is a commonly used method for preparing 17-4PH stainless steel powder. The advantage of this method is that powders with higher density and finer particle size can be prepared. At the same time, the method can also add different elements during the production process, thus adjusting the composition and properties of the powder convenient. However, the disadvantage of this method is that the equipment cost is high and the production accuracy is also affected by the gas rate.

Mechanical ball milling is an economical and practical method for preparing 17-4PH stainless steel powder. The principle of the method is that the raw materials of stainless-steel  powder are impinged, flattened and scraped by high-energy ball milling, so as to achieve the crushing and mechanical synthesis of the stainless-steel raw material powder. Although the powder preparation of this method is relatively simple, its disadvantage is that it needs to prepare stainless steel powder with high shear and scraping strength, otherwise it will affect its subsequent selective laser melting forming effect.

Chemical reduction method is a new method for preparing 17-4PH stainless steel powder. The principle of this method is to use chemical reactions to convert stainless steel raw materials into powder through reduction reaction. The advantage of this method is that it is more environmentally friendly and can obtain high quality and uniform distribution of stainless-steel powder. However, in practical application, the process of this method is complicated, and the particle size control of powder is difficult.

As mentioned above, 17-4PH stainless-steel powder has three preparation methods: inert gas atomization, mechanical ball milling and chemical reduction. The production of the powder have an important impact on the forming process and finished product properties.Amongthem, inert gas atomization method is a commonly used for 17-4PH stainless steel of selective laser melting forming material, because in order to ensure the finished quality of 17-4PH stainless steel powder, it is necessary to strictly control its composition, particle size and shape parameters during the powder preparation process, and carry out subsequent compression and drying treatment, so as to form a more complete powder particles.