The enhanced MR performance of dimorphic MR suspensions containing either magnetic rods or their non-magnetic analogs. (24th January 2017)

• Record Type: Journal Article
• Authors: Plachy, Tomas; Cvek, Martin; Kozakova, Zuzana; Sedlacik, Michal; Moucka, Robert
• Is Part Of: Smart materials and structures. Volume 26:Number 2(2017:Feb.)
• Publication Date: 2017-01-24
• Subjects: magnetorheology -- magnetorheological effect -- dimorphic fluid -- ferrous oxalate -- iron oxide -- morphology -- sedimentation stability; Smart materials -- Periodicals; Strucural design -- Periodicals; 620.11
• DOI: 10.1088/1361-665X/aa56ef
• Languages: English
• ISSNs: 0964-1726

Abstract

Abstract: A co-precipitation method was used to prepare non-magnetic rod-like ferrous oxalate dihydrate (Fe2 CO4 · 2H2 O) particles that were further turned into iron oxide (Fe3 O4 ) magnetic rod-like particles. A simple precursor-assisted thermal decomposition technique enabled the preservation of the morphology and size of the precursor ferrous oxalate dihydrate particles, thus allowing their magnetic analogs to be obtained. Both types of rod-like particles were used as an additive together with spherical carbonyl iron (CI) particles in novel dimorphic magnetorheological (MR) suspensions. Controlled shear rate mode experiments were performed using a rotational rheometer with a source of an external magnetic field in order to investigate their MR behavior. Moreover, the properties of the novel prepared dimorphic MR (DMR) suspensions were compared with conventional MR suspensions based on spherical CI microparticles. It was found that the DMR suspensions exhibit enhanced MR performance as well as enhanced sedimentation stability in comparison with the MR suspension based on pure CI. The dimorphic suspensions containing magnetic rod-like additives further exhibited significant MR hardening at low shear rates. The properties of CI-based suspensions can be thus optimized by using various additive substances.