【作者】 李春红；

【导师】 曾苏民；

【作者基本信息】 西南大学 ， 材料物理与化学， 2009， 硕士

【摘要】 本论文选以1050铝合金和1052铝合金为原料,经过熔铸、均匀化处理、热轧、中间退火、冷轧工艺,各工艺采用相同的参数,对成品试样金相显微组织、力学性能和电解腐蚀性能进行比较,选出性能较好的铝合金。以此铝合金为原料,改变热轧变形量、变形温度、中间退火温度、冷轧变形量,结合金相显微组织,电镜微观组织观察各因素对性能的影响,得到综合性能较好的制备工艺。分析了显微组织对力学性能与电解腐蚀性能的影响,并在制备过程中采取措施提高材料的表面性能。结果表明如下:(1)1052铝合金中的Mg元素含量比1050中多,Mg元素对晶粒长大有抑制作用,并能提高纯铝的再结晶温度,所以1052铝合金板晶粒比1050铝合金板晶粒细小均匀,这有利于提高铝合金板的强度和腐蚀性能,并且1052铝合金板表面Mg元素的富集分布和形成的氧化镁利于提高板基的腐蚀性能。因此用1052铝合金制成的PS板基比用1050铝合金制成的好。(2)在470℃热轧,420℃/1h中间退火条件下,试样的力学性能主要由冷轧变形量决定,而未进行中间退火的试样由热轧变形量和冷轧变形量共同决定。未经过中间退火的试样冷轧变形量85%的硬度最高,经过中间退火的试样冷轧变形量90%的硬度最高。且经过中间退火的试样的力学性能和电解腐蚀性能比未经过中间退火的好。(3)热轧温度380℃,中间退火380℃/1h,热轧变形量为88%,冷轧变形量为85%时,得到的性能最好,抗拉强度209.7MPa,屈服强度为206.2Mpa,延伸率为3.4%,平均晶粒为15.1μm。在2.5%(体积分数)的HCl水溶液中,试样的电解腐蚀电流密度可高达4.021E-5A/cm~2,自腐蚀电位达到-0.7358V,腐蚀均匀性好,腐蚀后表面形貌孔洞尺寸较小,形状规则,分布均匀。(4)轧制过程中产生大量位错,位错边界分割晶粒而使晶粒细化,热轧过程中的动态再结晶和热轧后的退火都有细化晶粒作用,因此此工艺使晶粒得到较大细化,晶粒可以从210μm左右减小到15μm左右。试样的显微硬度随着晶粒的减小而提高。更多还原

【Abstract】 By analyzing and comparing the microstructures,mechanical properties and electrolytic corrosion properties of 1050 and 1052 Aluminum alloys produced by the same forming parameters of melt casting,homogenization treatment,hot rolling, intermediate annealing and cold rolling,the alloy with better properties was chosen for further study.The effects of hot-rolling reduction,deformation temperature, intermediate-annealing temperature and cold-rolling reduction on mechanical properties of the chosen alloy were investigated by optical microscopy and electron-microscopy, and the processing parameters to get better mechanical properties were obtained.The effects of microstructures on mechanical and corrosion properties were also studied and suitable methods were adopted to improve the surface quality of the aluminum substrate plate.The main conclusions from experiments can be drawn as follows:(1)The content of Mg in 1052 is larger than that in 1050 alloy,which can restrains grains in the alloys from growing and then increase the recrystallization temperature. Hence,the grain size of 1052 alloy is smaller than that of 1050 alloy,benefiting to improve the mechanical and corrosion properties of the former alloy.At the same time, a larger mount of Mg content with oxide MgO distributed on the surfaces of 1052 alloy plate is beneficial to increasing its corrosion properties.(2)Given that the samples are hot-rolled at 470℃and intermediate-annealed at 420℃for 1h,the mechanical properties are mainly determined by the cold-rolling reduction.While for the samples without intermediate-annealing treatment,their mechanical properties are determined by both hot rolling and cold rolling reductions. The sample with 85%cold-rolling reduction and without intermediate-annealing treatment has the highest hardness.However,the sample with 90%cold-rolling reduction with intermediate-annealing treatment possesses the highest hardness.And at the same time,its mechanical and corrosion properties are better than those of the sample without intermediate-arinealing treatment.(3)The sample hot rolled at 380℃with deformation reduction 88%,intermediate annealed at 38℃for 1h and cold rolled with deformation reduction 85%has the best mechanical properties(namely,yield strength 206MPa,tensile strength 209.7MPa and elongation to failure 3.4%,and the average grain size is about 15.1μm..Under 2.5 percent of(volume fraction) of Hcl aqueous solution,the corrosion current density is 4.021E-5 A/cm~2,corrosion potential is -0.7358 V,respectively,and the corrosion cavity is fine and uniform.(4)A large amount of dislocations are generated during rolling,and the substructure formed by dislocations is fine.The dynamic recrystallization during hot rolling and the followed intermediate annealing can refine,gains.The grain size of the alloy can be refined from 210 to 15.1μm through the current preparation technologies,and the microhardness of the alloy becomes higher with smaller grain size.更多还原