| The bronze with good corrosion resistance, high strength and wear resistance, which is widely used on the market bearing bushings, taps, high pressure valves and other fields, but the presence of the melting temperature alloy casting forming high, short die life, segregation and other issues, and therefore need to develop new forming technology. Semi-solid forming has a short process, low energy consumption, less investment in equipment, cost savings and other advantages, and therefore carry bronze semi-solid forming has significance and value. In this paper, the ZCuSn10 bronze for the study, the use of flow forming technology, by cold-remelting method of preparing a slurry rheology, research holding temperature, holding time and rolling pre-deformation and other pulping process parameters and the pressing force extrusion speed and extrusion die structure, process parameters on the semi-solid alloy extrusion ZCuSn10 affect the organization, as well as by optical microscopy (OM), Brinell hardness, scanning electron microscopy (SEM) and tensile testing machines and other equipment, squeeze casting and rheological properties of tissue for analysis, to explore variation ZCuSn10 alloy filling flow deformation mechanism and tensile properties. The main contents and results of this study are as follows:(1) The pulping process for different parameters, the ZCuSn10 alloy extrusion microstructure get big difference; it is mainly manifested in the microstructure of extrusion rate which is the liquid and solid phases grain size and roundness various, other studies have shown that:the test results byheating 920℃, insulation 90min, rolling reduction of 17% can be obtained smooth surface, fewer defects macro squeeze casting, good roundness of their microstructure, fine particles, uniform distribution of the solid-liquid two-phase, indicating ZCuSn10 alloy has good rheological extrudability.(2) The different parameters of extrusion process, the differences filling flow deformation mechanism of ZCuSn10 alloy, so that the different of final microstructure squeeze significantly. Experimental studies have shown results that:by extrusion pressure 120T, extrusion rate of 15mm/s, no runner structure squeeze casting mold under homogeneous conditions, fine particles formed parts; there is mold runner structural microstructure of 25mm diameter squeeze casting is relatively uniform, but was no runner extrusion die casting organization structure to be worse; by analyzing the filling flow deformation mechanism shows that this is due to the simple structure of the mold paste filling process in various parts of the force uniform, solid-liquid two-phase flow synergies, which have a more uniform texture. After indenter diameter φ2.5mm Brinell hardness test:the typical parts (a) liquid cast copper alloy parts hardness 107.6HBW, liquid copper alloy extruded parts hardness of 110 HBW, showed that after extrusion, cast alloy ZCuSn10 hardness; liquid copper alloy extruded parts, extruded disc copper alloy semi-solid simple parts and extruded semi-solid copper alloy parts typical complex parts a, b, c cloth hardness was 110 HBW,114 HBW,112 HBW and 145.8HBW,148 HBW,146 HBW and 125.4 HBW,132 HBW,115 HBW.(3) The microstructure and performance between analysis of the cast, semi-solid and heat before melting extrusion of semi-solid. The results show that:the cast tensile strength 317.4MPa, elongation of 15.8%, the tensile strength of the semi-solid remelting 328.1MPa, elongation of 16%; extruded semi-solid casting filling process of the microstructure due to the uneven and can not characterize specific strength. by α phase and α+δ phase change Sn content, heat treatment improved extrusion organization, performance improvement, which is heated 690℃ heat insulation 100min after air-cooled alloy extrusion ZCuSn10 pressure organization improve better, all parts of its original strength by the tensile strength tends to be uneven uniform, the final tensile strength of 344.5MPa, an elongation of 17.7%. |
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