| By using natural granite granule as aggregate and organic resin as binder, resin mineral composite is superior in its good forming ability, high casting accuracy, good damping vibration attenuation, good thermostability and high corrosion resistance, which is appropriate to manufacture basic parts of high-speed and high-precise machine tool, laser machinery, electronic equipment and armarium, such as lathe bed, base, workbench and column.Even though resin mineral composite has lots of good characteristics which cast iron doesn’t have, the mechanical property of resin mineral composite is quite low, which limits its widespread use in industrial production to a large extend. In this paper, steel fiber reinforced resin mineral composite is prepared, and the bending strength and compressive strength of resin mineral composite have improved obviously due to the addition of steel fiber. Different surface pretreatment methods are applied to explore the main factors influencing the interface bonding strength and mechanical property of resin mineral composite. These researches lay a foundation of resin mineral composite’s industrial application as basic parts in machine tools.According to the different chemical characteristics and industrial production requirements, optimizing the composition of fiber reinforced resin mineral composite, such as organic resin, curing agent, diluent, aggregate, filler and reinforcing fiber. With reference to the existing mature experience in preparation of composite materials and combining the field test results, optimize the process routing of steel fiber reinforced resin mineral composite.On the basis of mechanism of steel fiber’s surface pretreatment, experiment are carried out to study the influence of different surface pretreatment methods on steel fiber’s physical and chemical properties. Contact angle test show that the metal specimens’ surface free energies after surface pretreatments have varying degrees of increase compared with untreated ones, especially the ones after oxidation, have increased by 82.3%. The increase of surface free energy improves the infiltration capacity of metal surface and is conducive to the infiltration and spreading of epoxy resin. Pull-out test of single steel fiber show that the bond strength of steel fiber and resin after surface pretreatments have varying degrees of increase compared with untreated ones. The ones after coupling treatment perform the best, have an increase of 45.1%, because of the dual effect of increased surface free energy and interpenetrating or semi-interpenetrating network layer between steel fiber and epoxy resin. Combined with steel fiber’s tensile strength test and pull-out test, the formula of reinforcing fiber’s critical length is derived when the maximum debonding force is equal to the maximum tensile strength.In the performance research of steel fiber reinforced resin mineral composite, we find that composite material’s mechanical properties can be effectively improved by adding steel fiber, and the bending strength and compressive strength increase by 17.9% and 8.2%, respectively. The addition of steel fiber can improve the sharp crack propagation phenomenon at the beginning of the load, and at the end of the load, the debonding process between steel fiber and resin need absorb lots of energy and the composite exhibits a good moulding. In the experimental study of the effect of surface pretreatment on the steel fiber reinforced resin mineral composite’s performance, we find that surface pretreatment can apparently improve the bending strength but less affect the compression strength. Among all the four surface pretreatment methods, the specimens after coupling treatment behave the best and have an increase of 33.4% in bending strength. |
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