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

作者：Mueller Camila; Leonardo Redondo Franco; Dennehy Mariana; Eduardo Ciolino Andres; Roberto Tuckart Walter

来源：Industrial Lubrication and Tribology, 2018, 70(2): 347-352.

DOI：10.1108/ILT-03-2017-0051

• Additives
• Lubricity
• Bismuth (III) sulfide
• Poly(dimethylsiloxane)
• Reichert's test

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.

• 出版日期2018