【作者】 谢懿；

【导师】 李荣德； 刘敬福；

【作者基本信息】 沈阳工业大学 ， 材料加工工程， 2009， 硕士

【摘要】 本文采用喷射沉积方法制备高锰ZA35合金,通过对比挤压温度和挤压比在热挤压过程中对合金性能的影响,得出合金的最佳热挤压工艺参数为挤压温度260℃挤压比21.7,并研究了合金在最佳挤压工艺下的高温热稳定性能和组织变化。研究表明:同一挤压温度下,随着挤压比的增加,合金的常温力学性能快速增加;挤压比为21左右时,合金的力学性能达到最大,增大挤压比到33.8,合金的力学性能反而降低;同一挤压比下,合金的力学性能随挤压温度的增加而降低。挤压温度260℃挤压比21.7合金的常温力学性能最好;抗拉强度491.2MPa,伸长率5.19%,硬度151HBS。随着挤压比的增加,坯体基体组织逐渐细化,空隙减少,析出相分布均匀;然而过高的挤压比导致合金基体组织粗大,第二相聚集,分布集中。260℃挤压的合金组织含有α-Al、η-Zn、Mg₃₂（AlZn）₁₉、Al₁₁Cu₅Mn₃、MnAl₆、CuMnZn;380℃挤压时,合金中的Cu,Mn过饱和固溶体发生脱溶,与基体元素Zn形成CuZn₆相。在转速相同的情况下,挤压温度260℃挤压比21.7合金的摩擦系数比挤压温度320℃挤压比21.7合金的摩擦系数低7.8%,在载荷相同的情况下,挤压温度260℃挤压比21.7合金的摩擦系数比挤压温度320℃合金的摩擦系数挤压比21.7低11.77%。在150℃热暴露时,挤压温度260℃挤压比21.7合金的强度先提高再降低,合金中Cu、Mn析出形成MnZnAl₃和CuAl;200℃热暴露时,其强度降低,合金中的Cu、Mn元素快速析出形成MnCuAlZn四元合金相和MnCuAlMgZn相。更多还原

【Abstract】 In this paper,ZA35-3.5Mn alloy is formed by spray deposition.The microstructure of the alloy under different squeezed parameters was studied,a better squeezing parameter that is temperature 260℃ratio 21.7 could be obtained with applying direct analysis.The results indicate that at the same squeezed temperature,when squeezed ratio is increased,the tensile strength,hardness and elongation of alloy are increased quickly, when ratio becomes 21,the best mechanical property is obtained,but increasing the ratio to 33.8,the mechanical property is decreased;at the same squeezed ratio,with the squeezed temperature increased,the tensile strength,hardness and elongation of alloy is decreased. the mechanical property of alloy by temperature 260℃ratio 21.7 at room temperature is the best,that tensile strength is 491.2 MPa,elongation is 5.19%,hardness is 151 HBS.According to the analysis on the microstructure,the results show that the phase compositions of ZA35-3.SMn alloy by temperature 260℃areα-Al,η-Zn,Mg₃₂（AlZn）₁₉, Al₁₁Cu₅Mn₃,MnAl₆,CuMnZn;when temperature increases to 380℃,phase CuZn₆ is generated.With ratio increases,the grains can be refined,initial phases tum from rough grains into uniformly distributed fine ones;the pore space is fade;But using overtop ratio, the grains grow rapidly,phases are aggregated and distributed of concentrated.To compare with alloy squeezed at 320℃,the friction coefficient of alloy squeezed at 260℃reduces to 16.69%at the same rotation speed.When applying load is the same, the friction coefficient of alloy squeezed at 260℃reduces to 17.37%.Mn phase as hard phase can bear heavier load,which makes ZA35-3.5Mn alloy by spray deposition having better wear and friction properties.While exposed at 150℃,the strength of alloy at 260℃ratio 21.7 is enhanced and Cu,Mn in the alloy are precipitated as MnZnAl₃ and CuAl;and while exposed at 200℃, the strength of the alloy is reduced,Cu,Mn are rapidly precipitated in the formation of phase MnCuAlZn and MnCuAlMgZn.更多还原