Bismuth (III) sulfide as additive: towards better lubricity without toxicity
Abstract
Purpose
The purpose of this study is to design a fluid formulation with good lubricant properties by using an environmentally friendly additive for: high and low contact pressure conditions and steel/steel and polymer/steel systems.
Design/methodology/approach
Bismuth (III) sulfide (Bi2S3, “green chemistry” synthesis) is added to a commercial vinyl-terminated silicone fluid (PDMS-Vi) to obtain different weight-per cent mixtures. Tribological performance of formulations is studied from Reichert’s tests (steel/steel system) and block on ring tests (polymer/steel). The results are compared with formulations prepared with commercial bismuth (III) sulfide (Bi2S3), molybdenum (IV) sulfide (MoS2) and graphite.
Findings
An orthorhombic crystal lattice (XRD ) and a high-purity product (XRF) are evidenced for synthesized Bi2S3. Lubricant properties increase when the weight-per cent of the synthesized Bi2S3 increases in formulations. The wear area decreases up to 90 per cent according to Reichert’s tests. The synthesized Bi2S3 shows a better tribological behavior when compared to commercial Bi2S3, MoS2 and graphite.
Originality/value
Replacement of lead derivatives by an environmentally friendly lubricant in extreme pressure (EP) formulations and excellent performance compared to commercially used additives are achieved.
Keywords
Acknowledgements
The Universidad Nacional del Sur (UNS) and Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET) is acknowledged for financial support. The authors thank Miss Vivina Hanazumi for the SEC analysis.
Citation
Müller, C., Redondo, F.L., Dennehy, M., Ciolino, A.E. and Tuckart, W.R. (2018), "Bismuth (III) sulfide as additive: towards better lubricity without toxicity", Industrial Lubrication and Tribology, Vol. 70 No. 2, pp. 347-352. https://doi.org/10.1108/ILT-03-2017-0051
Publisher
:Emerald Publishing Limited
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