预热温度对等径角轧制6016铝合金织构及力学性能的影响

Texture Evolution and Mechanical Properties of 6016 Aluminum Alloys as Equal Channel Angular Rolling at Different Preheat Temperatures

通过准静态单轴拉伸实验、金相显微镜（OM）观察以及X射线衍射（XRD）宏观织构测试手段研究了3种不同预热温度（20,210,420℃）对等径角轧制6016铝合金板材的微观组织、织构及力学性能的影响。结果表明：在20,210,420℃3个温度范围内,随着温度的升高,RT（轧制）态板材的Brass{011}〈211〉织构、Copper{112}〈111〉织构、S{123}〈634〉织构等形变织构取向密度和体积分数降低;T4P（固溶＋预时效＋自然时效）态板材的Cube{001}〈100〉织构的取向密度和体积分数逐渐降低,而斯密特因子逐渐升高,织构逐渐离散弱化。在420℃条件下,RT态板材发生动态再结晶,形变织构尚存,但取向密度和体积分数非常低,此外还出现了少量向再结晶织构转变的中间态织构;T4P态板材出现了少量的P{011}〈112〉织构、Goss{110}〈001〉织构和其他一些不常见的织构类型,各种织构强度较弱,没有强烈的再结晶织构,织构无序分布。在420℃条件下的T4P态板材具有良好的塑性和成形性,其δ〉29%,σ0.2〈110 MPa,r≈0.75,Δr≈0.16。而T8X（固溶＋预时效＋自然时效＋模拟烤漆硬化）态板材具有良好的烘烤硬化性能,其σ0.2〉210 MPa,σb〉335 MPa。

With the quasi-static uniaxial tensile experiment,optical microscopy（OM） and X-ray diffraction（XRD） macro texture methods,the effects of three different plate preheat temperatures（20,210,420 ℃） on the microstructure evolution,texture evolution and mechanical properties of 6016 aluminum alloys as equal channel angular rolling were studied. It showed that the intensity and volume fraction of Brass{011} 〈 211 〉,Copper{112} 〈 111 〉,S{123} 〈 634 〉 and other deformation textures of RT（rolled state）sample decreased with the temperature rising from 20 to 210 ℃ and to 420 ℃. The study also showed that the intensity and volume fraction of Cube{001} 〈 100 〉 texture of T4P（solution ＋ pre-aging ＋ naturally aging） sample gradually decreased. When the Schmidt factor increased,and the texture was weakened and scattered. When the preheat temperature arrived at 420 ℃,the RT sample was dynamically recrystallized,and deformed textures still existed in the sheet but the intensity and volume fraction were pretty low. With this temperature condition,there were small amount of intermediate state textures converting to recrystallization textures. And the T4P sample had a little P{011} 〈 112 〉,Goss{110} 〈 001 〉 textures and some unusual textures featuring low intensity and disordered distribution but no strong recrystallization textures. Along with 420 ℃ as preheat temperature,the T4P sample showed good elongation（δ 〉29%）,and formability（σ0. 2〈 110 MPa,r≈0. 75,Δr≈0. 16）,while T8X（solution ＋ pre-aging ＋ naturally aging ＋ bake hardening） sample owned good bake hardening response（σ0. 2〉 210 MPa,σb〉 335 MPa）.