Metal Injection Molding: its Materials and Utilities

The catalog of MIM materials available at ECRIMESA covers the main needs of industrial sectors in automotive, machinery, defense, medicine or sports.

The variety of compositions and heat treatments allows us to work with sectors as diverse as automotive, machine tools, defense, medicine, sports, among others.

Low alloy steels

• These are carbon steels containing alloying elements in order to improve their properties. Low alloy steels are those containing from 1% to 4% alloying elements and are mainly used in the automotive, defense, industrial machinery, machine tools, locksmithing, etc. sectors. Normally, this type of steel achieves its final properties after heat treatment, surface treatment or a combination of both after sintering. The most common heat treatments for this type of steel are quenching, tempering and carburizing. Surface treatments can also be applied to improve resistance to the elements, such as bluing, nickel plating, zinc plating and Tenifer QPQ, among others.

• The following table details the nomenclature of the different low alloy steels, according to the specific ISO or ASTM standard, and the chemical composition they contain: 
  
  It should be noted that this group includes steels high in Nickel percentage coming from traditional powder metallurgy (PM / Press and sinter) but with much better mechanical properties due to the high density achieved with MIM technology.  
  
  Also included are low alloy steels whose designation is taken from traditional manufacturing standards such as DIN/EN or SAE, however, there are still steels that have not been standardized for MIM according to ISO 22068.  

• The following table describes the mechanical properties of low-alloy steels as a function of the heat treatment applied:  

• In blue, the minimum standardized properties according to MIM ISO 22068 standard. In green, typical results obtained in our laboratory with specimens processed in our own processes.  

• A large part of Ecrimesa Group’s production is manufactured with low alloy steel FN08. This has led us to acquire extensive experience and knowledge about the behavior of this type of steel when processed using MIM technology.  

Tool steels

• Tool steels are designed for applications where high wear resistance is required. They are steels that have a high carbon content and have alloying elements (Cr, Mo, V) capable of forming high hardness carbides in the material. Hardness values >65 HRC can be achieved for heat-treated tool steels.  

• The following table lists the tool steels we work with in the Group and their chemical composition: 

• The mechanical properties as a function of the heat treatment applied are shown in the following table: 

• Application examples of tool steels:  

Soft Magnetic Steels

• Soft magnetic steels have the ability to magnetize and demagnetize easily and quickly when a magnetic field is applied or removed. One of their applications within an electromagnetic field could be to transform motion into an electrical signal or vice versa. The magnetic properties of these materials make them ideal for electronic applications, electrical machines, actuators, sensors and, in short, for all types of solutions with magnetic needs. 

• The soft magnetic steels available at Ecrimesa are:  

• In the following table we can see the mechanical properties of sintered soft magnetic steels and their properties:

Stainless Steels

• Stainless steels are characterized by their high resistance to corrosion in aggressive environments. They are highly alloyed steels with a percentage of Cr >12% and a low percentage of C, since this element reduces the corrosion resistance of the steel. Depending on the properties of the stainless steel, we can classify them into ferritic, martensitic, precipitation hardening and austenitic stainless steels. Their processing by means of MIM technology achieves an excellent surface finish which, together with the good properties of these materials, makes them particularly attractive for aesthetic applications. The application sectors of stainless steels are very diverse, the most relevant being sports, tools, defense, jewelry, medicine, automotive, aeronautics, among others. 

• The following is the classification and composition of the stainless steels manufactured by Ecrimesa:  

• 17-4PH is the most commonly used stainless steel. Its alloying elements make the steel harden by precipitation after heat treatment, providing excellent mechanical strength to its properties, as well as excellent corrosion resistance similar to other non-hardenable stainless steels. In Ecrimesa Group we have conducted an important study on the corrosion resistance and properties of 17-4PH, work presented at the EUROPM 2018 Congress & Exibition. In the conclusions we saw the importance of avoiding powder-binder phase segregation, heat treatment and surface finish in the corrosion resistance of 17-4PH, performing several studies in salt spray chamber.  

• The following table shows the mechanical properties depending on the heat treatment applied to the different stainless steels manufactured by Ecrimesa Group: 

Other materials

• Within the catalog of materials we can find some more particular compositions, with very specific characteristics for certain applications, such as refractory materials and nickel-based superalloys used in parts that need resistance in high temperature work. 

In Ecrimesa Group we have a large development and industrialization team and we also have experience in the development of materials on demand as well as parts that are at the limits set by MIM technology.  

To learn more about the MIM materials we use in Ecrimesa Group: