GE T
A review of the sintering of iron-copper-carbon alloys for structural Powder Metallurgy applications Iron-copper-carbon alloys have been used for structural Powder Metallurgy applications for more than half a century and, to this day, they remain popular for the production of automotive components. In this comprehensive review, Prof Randall German covers the sintering of iron-copper-carbon alloys, with a focus on the popular composition FC-0208. The review, which is intended to help producers to optimise properties as well as identify future research needs, explores powder characteristics, processing conditions, and the response parameters of mechanical properties and dimensional control.
This review focuses on the sintering of an important Powder Metallurgy alloy based on iron, copper, and carbon. A popular composition consists of iron with 2% copper and 0.8% carbon, designated FC-0208. The alloy has been used for structural applications since at least the 1950s and remains a favourite for fabrication of automotive components. Detailed here are linkages between powder characteristics, processing conditions, and response parameters of mechanical properties and size change (dimensional control). The sequence of events during sintering are detailed in terms of copper melting, spreading, and grain boundary penetration along with carbon diffusion. The balance between these aspects, as well as post-sintering heat treatment, determines the mechanical properties. This compilation is intended to help optimise properties and identify needed research. Powder Metallurgy consists of several forming alternatives that rely on high sintering temperatures
© 2023 Inovar Communications Ltd
to bond the particles. In the case of the iron-copper-carbon alloys, sintering is at a temperature greater than the copper melting point (1,083°C). The melting of copper leads to significant strengthening as required for structural applications.
There is no equivalent composition in cast or forged metallurgy. This is because castings would undergo deleterious copper segregation to boundaries and interfaces during cooling, leading to a problem known as hot shortness. Thus,
Fig. 1 An FC-0208 copper steel drive pulley produced by Capstan Atlantic. It is used in the power steering of an electric autonomous vehicle and won an Award of Distinction in the Automotive – Electric Vehicle category for conventional PM components in the Metal Powder Industries Federation’s 2023 Design Excellence awards (Courtesy MPIF)
Winter 2023
PM Review
69
F
Sintering iron-copper-carbon PM parts
PD
| contents | news | advertisers | events | website | newsletter |