The effects of heat extrusion processing of spray forming TiCp/ZA35 composites on extrusion ratio, extrusion specific pressure, extrusion temperature and extrusion rate had been studied by artificial neural network (ANN). The artificial neural network model was created for heat extrusion processing. The input parameters of the ANN model were extrusion ratio, extrusion specific pressure, extrusion temperature and extrusion rate. The output of the ANN model was ultimate tensile strength. The model can be used for the prediction of properties of spray forming TiCp/ZA35 composites as functions of processing parameters. It can also be used for the optimization of the processing parameters. The ANN results are in good agreement with experimental phenomena, the biggest relative error and coincidence rate is less than 1.8% and 0.986. The optimized heat extrusion ratio, extrusion specific pressure, extrusion temperature and extrusion rate are 22415 MPa, 315 ℃ and 8 mm·s−1 respectively, and the tensile strength of spray forming TiCp/ZA35 composites is 486.7 MPa. The reinforcement phase MnAl6 whisker or particle is precipitated in the grains due to the indirect aging treatment of composites by hot extrusion. Dispersion strengthen and dislocation strengthen contribute a combination factor to increase the room temperature mechanical properties of the hot extruded TiCp/ZA35 composites, which is 38.3% higher than that of TiCp/ZA35 composites without heat extrusion.

采用热挤压对喷射沉积TiCp/ZA35复合材料进行致密化处理,分析挤压比压、挤压温度、挤压比及挤压速率对复合材料力学性能的影响.结果 表明:热挤压后,TiCp/ZA35复合材料中反应生成的增强相TiC颗粒在晶界和晶内分布均较均匀,组织中析出MnAl6强化相,相对密度提高;当挤压比压为430 MPa,温度为285℃,挤压比为12,速率为8 mm/s时,挤压后复合材料的抗拉强度为485.0 MPa、伸长率为9.53％.

Effect of heat treatment on microstructure and damping property of TiCp/ZA35 alloy composites fabricated by spray deposition in situ reaction was investigated.The results show that the TiCp/ZA35 alloy composites own fine grains and nearly spherical TiC particles distributed uniformly along the grain boundaries without obvious aggregation.The dislocation density is higher at the interface between TiC particles and ZA35 alloy matrix.The internal friction of TiCp/ZA35 alloy composites increases with the temperature rises, and decreases with the rise of test frequency, and goes up to 0.105 at 160℃and 1 Hz.The damping of TiCp/ZA35 alloy composites after 350℃×4 h+150℃×6 h heat treatment is 16.2％ higher than that without heat treatment, which is attributable to the dislocation internal friction and the interface internal friction between reinforcement TiC and ZA35 alloy matrix.

采用喷射沉积Al-Ti-C预制体和ZA35合金的混熔体制备原位反应TiCP/ZA35复合材料,对TiCP/ZA35复合材料进行固溶时效处理.利用金相显微镜、X射线衍射(XRD)和电化学工作站研究了固溶与时效处理后复合材料的组织和电化学性能.结果表明,TiCP/ZA35复合材料组织为细小等轴晶,TiC颗粒分布均匀.经过350℃×4h固溶+150℃×6h时效处理后,析出相主要是MnAl6和Al11Cu5Mn3.在3.5％ NaCl溶液中,经过350℃×4h固溶+150℃×6h时效处理的复合材料腐蚀电流密度最小,为0.005 mA/cm2,相对于未处理复合材料减小73.7％.适宜热处理相对于未处理复合材料的电阻增加和电极双电层电容下降是改善耐蚀性的主要原因.在本实验中,TiCP/ZA35复合材料最佳的热处理工艺是350℃×4h固溶+150℃×6h时效.

针对沿空留巷顶板下沉量大、控制十分困难的问题,在分析沿空留巷顶板下沉规律的基础上,利用能量守恒原理,建立了沿空留巷顶板下沉力学模型,推导出顶板下沉量的计算公式,并对顶板下沉的影响因素进行了定量分析和灰色关联度敏感性分析.结果表明:某矿沿空留巷顶板下沉量计算值为371.45 mm,较好地吻合现场测量值,理论计算公式是准确的.顶板下沉随巷道宽度、采高的增加而增大,随直接顶厚度、巷内支护阻力、煤帮侧向支护阻力、巷旁充填体宽度和充填体弹性模量的增加而减小;对沿空留巷顶板下沉的敏感度大小的影响因素依次为采高、充填体弹性模量、充填体宽度、直接顶厚度、巷内支护阻力、巷道宽度、煤帮侧向支护阻力,其关联度分别为0.96、0.73、0.68、0.52、0.28、0.13、0.04.研究结果可为有效控制沿空留巷围岩变形提供依据.