| This article adopts the method of powder metallurgy preparation of as-cast SND sp2 + Mg2B2O5w/ZK60 composites, and the preparation of composite materials in the form of 1:12 extrusion, extrusion ratio and after the extrusion of composites for heat treatment(annealing, quenching, aging). And use the thermal expansion instrument with different volume fraction and the composites of different heat treatment states for 30-400 ℃, the heating rate of 5 ℃ / min, a thermal cycling test for10 cycles. By optical microscope the microstructure before and after the extrusion were observed.By squeezing found that composite material grains obviously refined and combined more closely. Different volume fractions in extruded form composites after thermal cycling 30-400 ℃ was found with increasing volume fraction, not only thermal expansion coefficient of the material in descending reduced, and sawtooth phenomenon is also gradually reduced. As-cast ZK60 alloy and compared with extrusion composite material thermal cycle curvesl, found that the extrusion composite material sawtooth phenomenon significantly better than that of as-cast ZK60 alloys.Extruded composites of aging, hardening, annealing three kinds of heat treatment- aged, quenched, annealed three kinds of heat-treated composite. And The composites were 10 thermal cycles, the temperature range of 30-400 ℃, heating rate of 5 ℃ / min.Through the analysis of the thermal cycle curve that quenching state minimum sawtooth phenomenon of composite materials, the second is ageing, the biggest for annealing state but are better than that of extrusion state composite materials. After three kinds of heat treatment state of composite material thermal cycle of hysteresis loop is slightly better than its closing degree are extrusion composite materials.Thermal expansion coefficient and smaller than the extrusion composite materials. |
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