NTN Corporation, headquartered in Osaka, Japan, has developed a high-strength sintered alloy with a reported density of 7.6 g/cm3 or more and an endurance strength of 660 MPa (maximum stress 1467 MPa) or higher. This, states NTN, allows machine parts that require cutting processes, such as gears and bushes to be replaced with sintered alloys.
NTN developed a high-density sintered alloy in 2012, and has conducted further research to optimise the base powder, moulding, heat treatment and other processes with the aim of achieving a higher density and strength.
The use of a proprietary heat treatment process has improved the fatigue strength of gear teeth to 660 MPa, which is almost double that of NTN’s conventional sintered alloy products and similar to ordinary steel parts. NTN claims that this allows many types of machine parts to be replaced with this developed product, which was not possible with conventional sintered alloy products. A surface pressure strength, the index for surface stress on gears faces, of 2.3 GPa or more has been achieved.
NTN will not only apply this sintered alloy to machine parts, but also units and module products that feature combinations of resin parts and magnetic parts. The sintered alloy will also contribute to lower fuel consumption and electrification of automobiles, as well as enhance the reliability of industrial machinery components as part of efforts to achieve a reduction in environmental impact, states NTN.