BISMUTH (III) SULFIDE AS ADDITIVE: TOWARDS BETTER LUBRICITY WITHOUT TOXICITY

C. MULLER; F. REDONDO; M. DENNEHY; A. CIOLINO; W. TUCKART

INDUSTRIAL LUBRICATION AND TRIBOLOGY

EMERALD GROUP PUBLISHING LIMITED

Año: 2018 vol. 70 p. 347 - 352

0036-8792

To design a fluid formulation with good lubricant properties by using an eviromentally friendly additive for: i) high and low contact pressure conditions; ii) steel/steel and polymer/steel systems.Bismuth (III) sulfide (Bi2S3, ?green chemistry? synthesis) was added to a commercial vinyl-terminated silicone fluid (PDMS-Vi) to obtain different wt% mixtures. Tribological performance of formulations was studied from Reichert´s tests (steel/steel system) and block on rign tests (polymer/steel). The results were compared with formulations prepared with commercial bismuth (III) sulfide (Bi2S3), molybdenum (IV) sulfide (MoS2) and graphite.An orthorrombic crystal lattice (DRX) and a high-purity product (FRX) was evidenced for Bi2S3. Lubricant properties increase when wt% of Bi2S3 increases in formulations. Wear area decreases up to 90% according to Reichert´s tests. Bi2S3 shows a better tribological behavior when compared to commercial Bi2S3, MoS2 and graphite.Replacement of lead derivatives by an enviromentally friendly lubricant in EP formulations. Excellent performance compared to commercially used additives.