Bismuth (III) sulfide as additive: towards better lubricity without toxicity

MÜLLER, CAMILA; REDONDO, FRANCO LEONARDO; DENNEHY, MARIANA; CIOLINO, ANDRÉS EDUARDO; TUCKART, WALTER ROBERTO

INDUSTRIAL LUBRICATION AND TRIBOLOGY

EMERALD GROUP PUBLISHING LIMITED

Lugar: Londres; Año: 2018 vol. 70 p. 347 - 352

0036-8792

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.