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Magnetorheological gels typically are colloids of spherical micrometer magnetic particles dispersed in a high-viscosity polymer matrix. However, some major parameters of this kind of mono-disperse magnetorheological gel, such as the shear storage modulus and yield stress, cannot meet the needs of practical engineering application. In this study, a systematic experiment was investigated on the use of dendritic carbonyl iron particles to enhance the comprehensive performance in conventional (microsphere-based) magnetorheological gels formulated in polyurethane matrix. Two kinds of carbonyl iron particles that have very similar magnetic properties but very different morphologies (one is spherical and the other is dendritic) are employed. The dimorphic magnetorheological gels were prepared by adding dendritic carbonyl iron particles into the conventional spherical carbonyl iron particle–based magnetorheological gel and a series of dimorphic magnetorheological gel samples were prepared. The magnetorheological properties of those samples, both under oscillatory and rotational shear rheometry, were systematically tested. It was found that the dendritic carbonyl iron particle additives can significantly improve the shear storage modulus and response time of the dimorphic magnetorheological gels compared with conventional magnetorheological gels. Meanwhile, when the mass ratio of dendritic particles to carbonyl iron particles is 25% and 50%, the shear stress, static shear yield stress, and dynamic shear yield stress of dimorphic magnetorheological gels can also be greatly enhanced.

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Compression creep tests (CCTs) have been widely used in phenomenological characterization of viscoelastic materials such as glasses. However, disturbed by specimen‐tool interface friction, the real stress‐strain data regarding the pure viscoelastic deformation are frequently misestimated in conventional CCTs, causing decreased accuracies of the derived viscoelastic parameters. This study proposes a comprehensive CCT‐based approach to develop a viscoelastic model with weakened frictional disturbance and enhanced predictive accuracy. An integrated calculation procedure is first built to mathematically characterize the frictional and viscoelastic behaviors of glass during compression. Uniaxial CCTs of a typical borosilicate glass (L‐BAL42) are then performed at varied frictional conditions. The quantified coefficients of interface friction indicate that a minor frictional disturbance is achieved when Nickel foils are used as interfacial layers, whereby a more realistic viscoelastic constitutive relation of the glass is derived. The obtained frictional and viscoelastic constants are further incorporated into computational modeling of the CCT and precision molding processes. The demonstrated consistencies between the simulated and measured results (creep displacement and molding force) suggest that, by technically slashing the interface friction and theoretically correcting the friction‐involved stress in CCTs, the frictional disturbance to experimental stress‐strain data can be effectively weakened, and a viscoelastic model of enhanced predictive accuracy can be thus developed.