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论文类型：期刊论文

发表时间：2013-08-23

发表刊物：Advanced Materials Research

收录刊物：EI、CPCI-S、SCIE、Scopus

卷号：873

页面范围：325-332

ISSN号：9783037859698

关键字：Cement-based composite; Spiky spherical nickel powder; Pressure-sensitivity; Field emission effect; Tunneling effect; Pressure-sensitive characteristic model

摘要：A smart composite is fabricated from cement-matrix and spiky spherical nickel powders. The electrical resistivity of such composite decreases 69.00% under uniaxial compression. The gage factor of this composite is higher than 895.45 within the elastic regime. This ultrahigh pressure-sensitivity is attributed to the unique needle-like surface morphology of nickel powers. Comparing to the normal smooth spherical nickel particles, the needle-like features of spiky spherical nickel particles can induce field emission and tunneling effects, which leads to highly sensitive responses to strain. A constitutive model relating the change in electrical resistivity to strain of the composite is built within the elastic regime. This model incorporates the field emission effect and the inter-particle separation change of nickel powders in composite. The model is used to predict the pressure-sensitive characteristic behavior of the composite. The predicted result is compared with the experimental data obtained on the composite, and good agreement is obtained.