Studies on the Formation of Intermetallic
Compound Layers in Co(W)–Zn
Diffusion Couples
Tamara Ebner, Nadine Körbler, Stefan Luidold, Christoph Czettl
and Christian Storf
Abstract Cemented carbides are a composite material which consists of a hard
phase and a binder metal. At the end of their product lifecycle, these commodities
can be recycled by the zinc process. In the first step of this method, the scrap reacts
with molten zinc at elevated temperatures, which forms intermetallic phases with the
binder (Co) resulting in a disintegration of the material. By now, the exact mechanism
of this technique is not fully understood. Therefore, this research focuses on the
transactions between the binder and the liquid zinc by analysing the formation of
intermetallic phases via simultaneously varying decisive process parameters and the
composition of the binder metal. Hence, this study provides information regarding
the growth of intermetallic Co–Zn phases and emphasises the effect of dissolved
tungsten in the binder on the formation of these compounds.
Keywords Cemented carbide · Recycling · Zinc process · Co–Zn phases ·
Tungsten
Introduction
Due to the high hardness, thermal and wear resistances, cemented carbides are applied
in machining of metallic and non-metallic materials, chipless forming, wear parts,
nozzels, etc., and therefore, are an indispensable tool in the machining and mining industries. The combination of metallic carbides or carbonitrides and a metallic
binder results in a composite material, which exhibits a wide range of unique properties. In general, tungsten carbide (WC) serves as hard, wear-resistant and highmelting phase and is embedded in a tough and ductile metallic binder, such as Co.
The microstructure is defined by the WC grain size as well as the content of the binder
T. Ebner (B) · N. Körbler · S. Luidold
CD Laboratory for Extractive Metallurgy of Technological Metals, Montanuniversitaet Leoben,
Franz-Josef-Straße 18, 8700 Leoben, Austria
e-mail: tamara.ebner@unileoben.ac.at
C. Czettl · C. Storf
CERATIZIT Austria GmbH, Metallwerk-Plansee-Straße, 6600 Breitenwang, Austria
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_57
661
Compound Layers in Co(W)–Zn
Diffusion Couples
Tamara Ebner, Nadine Körbler, Stefan Luidold, Christoph Czettl
and Christian Storf
Abstract Cemented carbides are a composite material which consists of a hard
phase and a binder metal. At the end of their product lifecycle, these commodities
can be recycled by the zinc process. In the first step of this method, the scrap reacts
with molten zinc at elevated temperatures, which forms intermetallic phases with the
binder (Co) resulting in a disintegration of the material. By now, the exact mechanism
of this technique is not fully understood. Therefore, this research focuses on the
transactions between the binder and the liquid zinc by analysing the formation of
intermetallic phases via simultaneously varying decisive process parameters and the
composition of the binder metal. Hence, this study provides information regarding
the growth of intermetallic Co–Zn phases and emphasises the effect of dissolved
tungsten in the binder on the formation of these compounds.
Keywords Cemented carbide · Recycling · Zinc process · Co–Zn phases ·
Tungsten
Introduction
Due to the high hardness, thermal and wear resistances, cemented carbides are applied
in machining of metallic and non-metallic materials, chipless forming, wear parts,
nozzels, etc., and therefore, are an indispensable tool in the machining and mining industries. The combination of metallic carbides or carbonitrides and a metallic
binder results in a composite material, which exhibits a wide range of unique properties. In general, tungsten carbide (WC) serves as hard, wear-resistant and highmelting phase and is embedded in a tough and ductile metallic binder, such as Co.
The microstructure is defined by the WC grain size as well as the content of the binder
T. Ebner (B) · N. Körbler · S. Luidold
CD Laboratory for Extractive Metallurgy of Technological Metals, Montanuniversitaet Leoben,
Franz-Josef-Straße 18, 8700 Leoben, Austria
e-mail: tamara.ebner@unileoben.ac.at
C. Czettl · C. Storf
CERATIZIT Austria GmbH, Metallwerk-Plansee-Straße, 6600 Breitenwang, Austria
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_57
661