AMES offers in its catalog more than 150 types of sintered steels, which use a large variety of alloying elements, such as Mo, Ni, Cu, Cr or Mn. The final material properties are regulated based on its density, chemical composition, alloying technique of the alloying elements with the base iron, and possible heat treatments.

The following figure shows indicatively the level of tensile strength of sintered steels in comparison with the most widely used wrought steels. The graph demonstrates that powder metal steels can achieve a level of mechanical resistance equivalent to that of wrought alloyed steels by properly designing the alloy, maximizing the density of the component and/or applying heat treatments. The yield strength exhibits similar behavior.

The tensile and compressive yield strength limit and the hardness increase in linear proportion with the density. On the other hand, elongation, elastic modulus and dynamic characteristics, such as impact energy and fatigue limit, improve more sharply at high densities (> 7.2 g/cm³).

It is important to highlight that sintered steels are less sensitive to notching geometries than wrought steels.

Hardness of a powder metal steel is not valid to estimate its yield strength due to the microporosity of the material, but it is adequate to assess its compressive strength.

On the other hand, the wear resistance of a sintered steel is related to its microhardness. Porosity does not affect microhardness, as shown in the following figure, but it does affect apparent hardness (which considers the material microporosity).

The properties of these materials can be improved by applying certain special processes:

• Sinterhardening. It achieves high hardness at the exit of the sintering furnace, without the need for subsequent heat treatment.
• High temperature sintering. Increases density and improves mechanical properties, especially fatigue resistance and toughness.
• AmesDens-A^® and AmesDens-C^®. Processes to achieve very high density directly in the compaction operation, and therefore superior mechanical properties.
• SurfaDens^®. Surface densification of the teeth of a gear, which also improves the precision of the tooth profile. Suitable for gears that work in very demanding conditions.
• Ames-HAP^®. It allows the production of components of high hardness with great dimensional precision.

Sintered stainless steels are used in systems that require high corrosion resistance both at room temperature and at elevated temperatures.

The stainless steels offered by AMES to produce powder metal parts are AISI grades 303, 304, 316, 310, 409, 430, 434 and 410 (austenitic, ferritic and martensitic). The choice of material depends on the requirements for corrosion resistance, oxidation resistance at high temperature, hardness, mechanical strength or magnetism. Their corrosion properties vary considerably depending on the chemical composition of the material and the processing conditions.

AMES offers the Ames-SSP^® stainless steel with very high corrosion resistance (more than 2,000 hours in Salt Fog Spray chamber).