半固态ZCuSn10铜合金单向压缩组织演变与变形特性研究
发布时间：2018-08-26 15:46
【摘要】：半固态金属同时具有流变特性和触变特性,半固态加工技术作为一种先进的金属成形方法,集固态金属加工成形的力学性能好和液态金属加工的成形性好等优点于一体。为了研究半固态金属单向压缩的组织演变规律和变形特性,本文对半固态ZCuSn10铜合金进行了单向压缩实验。首先采用应变诱导熔化激活法(SIMA)制备半固态坯料,将半固态坯料加工成一定尺寸的圆柱形试样,再在Gleeble-1500试验机上进行单向压缩实验,分析了不同压缩参数下的显微组织的演变、变形特性和单向压缩过程中的变形机制,建立了半固态ZCuSn10铜合金的本构模型。主要研究结果如下：在Gleeble-1500热模拟试验机上对半固态ZCuSn10铜合金试样进行了单向压缩试验,得到其变形的真应力-应变曲线。通过在不同应变量、不同温度、不同应变速率的单向压缩实验,证明ZCuSn10铜合金的半固态压缩流变应力与温度、应变速率以及应变量具有相关性,在此基础上通过回归分析建立了半固态ZCuSn10铜合金变形的本构模型。此外,对半固态ZCuSn10铜合金和常规铸造ZCuSn10铜合金压缩变形时的研究表明：应变量、变形温度和应变速率对流变应力大小、显微组织变化和液相分布有显著影响,即相同变形条件下,半固态ZCuSn10铜合金的流变应力是常规铸造ZCuSn10铜合金的一半左右；随着应变量的增加,半固态ZCuSn10铜合金固液分离现象更加严重,自由变形区液相显著增加,应变量对峰值应力影响较小；随着应变速率的增加,峰值应力增加；随着温度的升高,自由变形区液相增加,峰值应力增加。半固态ZCuSn10铜合金在单向压缩过程中的变形机制包括：液相流动,即液相从等静压应力较大的晶界处流向等静压应力较小的晶界处,等静压应力较大的晶界一般垂直于压缩轴,等静压应力较小的晶界一般平行于压缩轴；固相晶界滑移转动,伴随液相流动变形的还有固液相混合流动；互相接触的固相晶粒间在压应力作用下的塑性变形。
[Abstract]:Semi-solid metal has both rheological and thixotropic properties. As an advanced metal forming method, semi-solid metal processing technology has the advantages of good mechanical properties of solid metal processing and good formability of liquid metal processing. In order to study the microstructure evolution and deformation characteristics of semisolid metal under unidirectional compression, unidirectional compression experiments were carried out on semisolid ZCuSn10 copper alloy. First, semisolid billets were prepared by strain induced melting activation method (SIMA). The semisolid billets were processed into cylindrical specimens of a certain size, and then unidirectional compression experiments were carried out on a Gleeble-1500 tester to analyze the evolution of microstructure under different compression parameters. The constitutive model of semisolid ZCuSn10 copper alloy was established by deformation characteristics and deformation mechanism during unidirectional compression. The main results are as follows: unidirectional compression tests were carried out on semi-solid ZCuSn10 copper alloy samples on Gleeble-1500 thermal simulation machine, and the true stress-strain curves of the samples were obtained. Through unidirectional compression experiments at different strain, different temperature and different strain rate, it is proved that the rheological stress of semisolid compression of ZCuSn10 copper alloy is correlated with temperature, strain rate and strain. On this basis, the constitutive model of semi-solid ZCuSn10 copper alloy deformation was established by regression analysis. In addition, during compression deformation of semisolid ZCuSn10 copper alloy and conventional cast ZCuSn10 copper alloy, it is shown that the strain, deformation temperature and strain rate have significant effects on the flow stress, microstructure change and liquid phase distribution. Under the same deformation condition, the flow stress of semisolid ZCuSn10 copper alloy is about half of that of conventional cast ZCuSn10 copper alloy, and with the increase of strain, the solid-liquid separation phenomenon of semisolid ZCuSn10 copper alloy becomes more serious, and the liquid phase in free deformation zone increases significantly. The strain has little effect on the peak stress; with the increase of strain rate, the peak stress increases; with the increase of temperature, the liquid phase increases and the peak stress increases in the free deformation zone. The deformation mechanism of semisolid ZCuSn10 copper alloy during unidirectional compression includes: liquid phase flow, that is, the liquid phase flows from the grain boundary with high isostatic pressure stress to the grain boundary where the isostatic pressure stress is small, and the grain boundary with higher isostatic pressure stress is generally perpendicular to the compression axis. The grain boundaries with small isostatic compressive stress are generally parallel to the compression axis; the solid grain boundary slips and rotates, accompanied by the solid-liquid mixed flow deformation; and the plastic deformation of the solid grains in contact with each other under the compressive stress.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG146.11
本文编号：2205378
[Abstract]:Semi-solid metal has both rheological and thixotropic properties. As an advanced metal forming method, semi-solid metal processing technology has the advantages of good mechanical properties of solid metal processing and good formability of liquid metal processing. In order to study the microstructure evolution and deformation characteristics of semisolid metal under unidirectional compression, unidirectional compression experiments were carried out on semisolid ZCuSn10 copper alloy. First, semisolid billets were prepared by strain induced melting activation method (SIMA). The semisolid billets were processed into cylindrical specimens of a certain size, and then unidirectional compression experiments were carried out on a Gleeble-1500 tester to analyze the evolution of microstructure under different compression parameters. The constitutive model of semisolid ZCuSn10 copper alloy was established by deformation characteristics and deformation mechanism during unidirectional compression. The main results are as follows: unidirectional compression tests were carried out on semi-solid ZCuSn10 copper alloy samples on Gleeble-1500 thermal simulation machine, and the true stress-strain curves of the samples were obtained. Through unidirectional compression experiments at different strain, different temperature and different strain rate, it is proved that the rheological stress of semisolid compression of ZCuSn10 copper alloy is correlated with temperature, strain rate and strain. On this basis, the constitutive model of semi-solid ZCuSn10 copper alloy deformation was established by regression analysis. In addition, during compression deformation of semisolid ZCuSn10 copper alloy and conventional cast ZCuSn10 copper alloy, it is shown that the strain, deformation temperature and strain rate have significant effects on the flow stress, microstructure change and liquid phase distribution. Under the same deformation condition, the flow stress of semisolid ZCuSn10 copper alloy is about half of that of conventional cast ZCuSn10 copper alloy, and with the increase of strain, the solid-liquid separation phenomenon of semisolid ZCuSn10 copper alloy becomes more serious, and the liquid phase in free deformation zone increases significantly. The strain has little effect on the peak stress; with the increase of strain rate, the peak stress increases; with the increase of temperature, the liquid phase increases and the peak stress increases in the free deformation zone. The deformation mechanism of semisolid ZCuSn10 copper alloy during unidirectional compression includes: liquid phase flow, that is, the liquid phase flows from the grain boundary with high isostatic pressure stress to the grain boundary where the isostatic pressure stress is small, and the grain boundary with higher isostatic pressure stress is generally perpendicular to the compression axis. The grain boundaries with small isostatic compressive stress are generally parallel to the compression axis; the solid grain boundary slips and rotates, accompanied by the solid-liquid mixed flow deformation; and the plastic deformation of the solid grains in contact with each other under the compressive stress.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG146.11
【参考文献】
相关期刊论文 前4条
1 杨卯生,毛卫民,钟雪友;半固态合金成形的技术现状与展望[J];包头钢铁学院学报;2001年02期
2 卢雅琳;李淼泉;;Al-4Cu-Mg合金的半固态变形及模型化研究[J];材料工程;2007年05期
3 毛卫民,殷爱美,钟雪友;半固态AZ91D镁合金的压缩变形研究[J];金属学报;2005年05期
4 王佳;肖寒;吴龙彪;卢德宏;周荣锋;周荣;;轧制-重熔SIMA法制备ZCuSn10合金半固态坯料[J];金属学报;2014年05期
相关硕士学位论文 前1条
1 谢礼志;铝合金半固态浆料制备工艺的研究[D];华中科技大学;2007年
，本文编号：2205378
本文链接：https://www.wllwen.com/kejilunwen/jinshugongy/2205378.html
教材专著
