TY - JOUR

T1 - Multilayer coatings based on the combination of perfluorinated organosilanes and nickel films for injection moulding tools

AU - Calderon, Juan Carlos

AU - Koch, Leon

AU - Bandl, Christine

AU - Kern, Wolfgang

AU - Jilg, Jannik

AU - Schilp, Catharina

AU - Moritzer, Elmar

AU - Grundmeier, Guido

PY - 2020/7/8

Y1 - 2020/7/8

N2 - Different multilayer coatings consisting of NiO and Ni layers supporting a 1H,1H,2H,2H-perfluorooctyltriethoxysilane/1,8-bis(triethoxysilyl)octane (PFOS) layer have been studied as possible alternatives for typical injection moulding tools. The NiO layer has been obtained by thermal annealing of an electroless Ni layer, whereas the PFOS layer was deposited by dip-coating. The physical and chemical properties of the as-coated steel have been studied by FIB-SEM-EDX, AFM, contact angle, Raman spectroscopy, X-ray photoelectron spectroscopy and PM-IRRAS. Furthermore, cyclic voltammetry, linear-sweep voltammetry, EIS and Mott-Schottky analyses were performed to determine the electrochemical properties of the coatings. Thermally grown NiO leads to a nanoporous surface layer with n-semiconducting properties, whereas the addition of the PFOS induced a decrease in the roughness of the studied samples. The corrosion resistance of the thermally grown NiO is strongly improved in comparison to the non-oxidised Ni-coating. Contact angles showed an effective reduction in surface energy on adsorbed PFOS-film. Injection-moulding tests using polyamide (PA6) and polyamide with 30% glass fibre content (PA6-GF30) were performed on a tool coated with PFOS/Ni to assess the anti-adhesive properties of this coating. After 150 cycles, the PFOS/Ni coating displayed remarkable stability, improved wear resistance and anti-adhesion properties to the studied polymers compared with the uncoated and TiN-coated tool.

AB - Different multilayer coatings consisting of NiO and Ni layers supporting a 1H,1H,2H,2H-perfluorooctyltriethoxysilane/1,8-bis(triethoxysilyl)octane (PFOS) layer have been studied as possible alternatives for typical injection moulding tools. The NiO layer has been obtained by thermal annealing of an electroless Ni layer, whereas the PFOS layer was deposited by dip-coating. The physical and chemical properties of the as-coated steel have been studied by FIB-SEM-EDX, AFM, contact angle, Raman spectroscopy, X-ray photoelectron spectroscopy and PM-IRRAS. Furthermore, cyclic voltammetry, linear-sweep voltammetry, EIS and Mott-Schottky analyses were performed to determine the electrochemical properties of the coatings. Thermally grown NiO leads to a nanoporous surface layer with n-semiconducting properties, whereas the addition of the PFOS induced a decrease in the roughness of the studied samples. The corrosion resistance of the thermally grown NiO is strongly improved in comparison to the non-oxidised Ni-coating. Contact angles showed an effective reduction in surface energy on adsorbed PFOS-film. Injection-moulding tests using polyamide (PA6) and polyamide with 30% glass fibre content (PA6-GF30) were performed on a tool coated with PFOS/Ni to assess the anti-adhesive properties of this coating. After 150 cycles, the PFOS/Ni coating displayed remarkable stability, improved wear resistance and anti-adhesion properties to the studied polymers compared with the uncoated and TiN-coated tool.

KW - Corrosion protection

KW - Electroless nickel

KW - PFOS organosilane

KW - Injection moulding

KW - Thermal oxidation

U2 - 10.1016/j.surfcoat.2020.126152

DO - 10.1016/j.surfcoat.2020.126152

M3 - Article

VL - 399.2020

JO - Surface & coatings technology

JF - Surface & coatings technology

SN - 0257-8972

IS - 15 October

ER -