径向挤压对Zn-15Al合金线材组织和性能的影响

为了改善锌铝合金线材加工使用性能,依据90°转角挤压原理,采用径向挤压出线工艺制取线材,研究了线材拉拔后的微观组织和力学性能,并与轴向挤压出线工艺进行对比.结果表明,径向挤压出线工艺可明显细化合金组织,且有纤维化倾向.线材抗拉强度降低15%,而伸长率提高30%.该工艺有利于线坯的拉拔加工,减少喷枪送丝途中的阻力.     

压力和Ti、B对ZnAl27Cu2合金组织和性能的影响

研究了挤压压力和Ti、B含量对ZnAl27Cu2合金组织和性能的影响.结果表明随着压力的增加,ZnAl27Cu2合金组织不断细化,强度、硬度和伸长率也相应得到提高;随着Ti、B含量的增加,合金组织和力学性能在得到一定改善后又逐渐恶化.     

挤压铸造对Al-Cu合金性能的影响

针对Al-Cu系合金，采取不同的成分配比及铸造，挤压铸造两种方法加工的试样进行实验，主要考察了配料成分，加工工艺及热处理工艺对合金力学性能的影响，发现试样在挤压铸造工艺下的组织及塑性较铸造的工件性能好，可提高组织致密性，硬度增加，力学性能得到改善。     

混合稀土和挤压铸造对ZL305合金组织和性能的影响

采用挤压铸造和重力铸造制备出不同混合稀土含量的ZL305合金,研究了混合稀土含量和挤压铸造对合金微观组织和力学性能的影响。结果表明,在重力铸造下,添加混合稀土对合金晶粒细化效果明显,当添加0.1%的混合稀土时,ZL305合金的综合力学性能达到最佳,抗拉强度增加到227.88MPa,伸长率为6.47%。相比重力铸造,挤压铸造成形的合金组织明显细化,并且合金铸态的抗拉强度和伸长率都明显提高。添加0.2%的混合稀土时,合金的抗拉强度和伸长率最佳,分别为302.35MPa和7.23%。经430℃×10h固溶处理后挤压铸造合金的性能显著提高。     

挤压变形程度对2A50合金组织性能的影响

通过试验的方法在不同变形程度等条件下对2A50合金进行性能测试和金相分析，结果表明经过挤压变形后，2A50合金晶粒被细化，纵向组织被拉长，铸造缺陷改善，力学性能提高。     

挤压工艺对7046铝合金型材组织与性能的影响

采用金相观察、SEM分析、力学性能测试等方法,研究了挤压工艺对7046铝合金型材显微组织与力学性能的影响.结果 表明:随着挤压温度和挤压速度的提高,合金的未溶相逐步溶入基体中,达到固溶强化的效果.但当挤压温度过高和挤压速度过低时,合金中的纤维组织发生静态回复再结晶,同时又析出稳定的第二相,经120℃24 h人工时效后,...     

锰对5056合金热挤压管材组织性能的影响

研究锰含量对5056铝合金热挤压状态管材组织和力学性能的影响。结果表明，由于5056合金中锰元素的含量少，对再结晶的抑制作用弱，使得挤出的管材组织发生了完生再结晶，从而使其力学性能与退火状态的基本相同，这就为在冷加工时，充分发挥合金的塑性，减少加工道次和退火次数，合理制定冷加工工艺提供了依据。     

往复挤压道次对车用LC9合金表面组织和性能的影响

采用光学显微镜、维氏硬度、极限拉伸强度和压缩屈服强度等试验手段,评价了不同往复挤压道次对LC9铝合金表面微观形貌和力学性能的影响。结果表明,往复挤压道次能显著影响LC9铝合金的组织和力学性能。合金的力学性能随着往复挤压道次的增加呈现出先增加后降低的趋势,500℃条件下当往复变形道次为4次时合金的力学性能最佳。     

挤压压力对挤压铸造ZL109铝合金组织和性能的影响

研究了挤压铸造过程中挤压压力对ZL109过共晶铝合金组织和性能的影响。试验选择在200 t液压机上进行挤压铸造,设计挤压压力为75 MPa、95 MPa、115 MPa进行评估。结果表明,挤压铸造工艺改善了铸件组织,提高了合金的力学性能。挤压压力的变化对合金的初生Si、共晶组织的尺寸、体积分数和力学性能影响显著。在试验范围内,挤压压力为115 MPa下的初生Si颗粒直径相较于75 MPa与95 MPa分别减小了23.5%和28.4%、共晶Si的平均尺寸分别减少了22.1%和50.3%;α-Al的尺寸分别降低了13.6%和18.3%;挤压压力从75 MPa增加到95 MPa,合金的抗拉强度、屈服强度、伸长率和硬度分别提高13.9%、22.6%、19.9%和9.4%;压力从95 MPa提高到115 MPa,抗拉强度和伸长率分别降低2.4%和6.6%。     

挤压变形对镁合金组织与力学性能的影响

研究了镁合金管材挤压成形工艺参数,如坯料温度、模具温度、润滑、挤压比、挤压速度等对镁合金管材挤压后组织与力学性能的影响,以及镁合金管材挤压成形后高温性能、室温性能和超塑性性能。结果表明:镁合金挤压管材的室温力学性能为屈服极限190 MPa,拉伸强度280 MPa,伸长率17%;镁合金挤压管材在400℃高温时的力学性能为屈服极限、拉伸强度值接近25MPa,伸长率180%;随着变形程度的增大,力学性能指标随之增大,并分析了镁合金管材挤压后组织状态的变化。     

Influence of hot extrusion on microstructure and mechanical properties ofAZ31 magnesium alloy

Extrusion treatment is a common method to refine the grain size and improve the mechanical properties of metal material. The influence of hot extrusion on microstructure and mechanical properties of AZ31 magnesium alloy was investigated. The results ,show that the mechanical properties of AZ31 alloy are obviously improved by extrusion treatment. The ultimate tensile strength （UTS） of AZ31 alloy at room temperature is measured to be 222 MPa, and is enhanced to 265.8 MPa after extrusion at 420℃. The yield tensile strength （YTS） of AZ31 alloy at room temperature is measured to be 84 MPa, and is enhanced to 201 MPa after extrusion at 420℃. The effective improvements on mechanical properties result from the formation of the finer grains during extrusion and the finer particles precipitated by age treatment. The features of the microstructure evolution during hot extruded of AZ31 alloy are dislocation slipping on the matrix and occurrence of the dynamic recrystallization.     

正挤压对铸态AZ31镁合金组织与性能的影响

为了研究塑性变形对铸态镁合金组织和性能的改善作用,用铸态AZ31镁合金进行了正挤压试验,并测试了原始试样和变形后试样的组织和性能.结果表明,正挤压可使铸态AZ31合金晶粒显著细化;挤压后抗拉强度和伸长率比挤压前分别提高22%和100%;随挤压温度升高,挤压所得试样的抗拉强度明显下降,但伸长率变化幅度较小;随挤压比的升高,挤压所得试样的伸长率和抗拉强度均明显升高.     

挤压轮转速对连续挤压铝锶合金成形及组织性能的影响

采用数值模拟与工艺实验相结合,研究了挤压轮转速对铝锶合金连续挤压成形过程和产品组织性能的影响。通过数值模拟分析了不同转速下坯料的温度、速度和等效应变分布情况以及模具的温度分布规律并利用金相观察和拉伸试验分析了不同转速下实际连续挤压产品的组织性能。结果表明,铝锶合金在连续挤压过程中,坯料进入腔体后,温度开始升高,最高温度和最大速度出现在模具出口处;最大等效应变出现在直角弯曲处。当挤压轮转速由4r·min~(-1)增加到7r·min~(-1)时,腔体内的坯料最高温度由460℃升高到514℃,模具出口处的温度由490℃升高到527℃;产品中Al4Sr相形态由块状变成颗粒状,尺寸减小;抗拉强度由98.7MPa上升到106.9MPa,伸长率变化不大,维持在约11%。     

挤压工艺对Mg-Sr-Y中间合金组织及力学性能的影响

研究了挤压工艺参数(挤压温度、挤压比)对Mg-Sr-Y中间合金组织和性能的影响。结果表明:Mg-Sr-Y中间合金的铸态组织是由树枝晶状的基体相α-Mg、沿晶分布的网状共晶组织(Mg17Sr2+Mg25Y4)组成;热挤压后合金的晶粒明显细化,树枝晶和网状组织被打碎,晶粒大小和合金中析出相的分布更均匀。同时挤压后合金的硬度显著提高,力学性能明显改善,形变强化效果较为显著,其强化效果与挤压温度和挤压比有关。挤压温度越高,挤压比越大,则强化效果越显著。     

Effect of hot extrusion on microstructure and mechanical properties of quasicrystal-reinforced Mg-Zn-Y alloy

The microstructure and mechanical properties of as-cast and as-extruded Mg-Zn-Y alloy （Mg-11 %Zn- 0.9%Y, mass fraction） containing Mg3 YZn6 quasicrystal were studied. The eutectic icosahedral quasicrystal phase （I-phase） is broken and almost distributes along the extrusion direction, and fine I-phase with nano-size is precipitated during the extrusion. The a-Mg matrix grains are refined due to recrystallization occuring during the hot extrusion. Some {1012} twins are observed in the extruded ZW1101 alloy. And {0002}（1010） fiber texture is formed in matrix alloys after hot extrusion. The extruded alloy exhibits high strength in combination with large elongation at room temperature. The strengthening mechanism of the as-extruded alloy was discussed.     

喷射成形Al-Zn-Mg-Cu合金挤压态的组织和力学性能

研究了利用喷射成形辅以挤压制备Al-5.72Zn-2.36Mg-1.66Cu合金后优化的组织结构特征和力学性能。结果表明,合金基体组织均匀细化,晶粒形貌趋于圆整,平均晶粒大小达到10 μm左右。当合金的冷却条件通过快速凝固技术改变时,会产生不同程度的固溶强化效果和第二相弥散强化效果,从而改善了合金的整体性能。合金的屈服强度和抗拉强度分别平均提高了20%左右,且伸长率也略有提高。     

Influence of ultrasonic melt treatment on microstructure and mechanical properties of AlSi9Cu3 alloy

A novel MMM (Multi-frequency, Multimode, Modulated) ultrasonic (US) technology was used to refine the as cast microstructure and improve the mechanical properties of a AlSi9Cu3 alloy. Ultrasonic vibration was isothermally applied to the melt for 120 s at different temperatures slightly above the liquidus temperature of the alloy, using different electric power values, before pouring into a metallic mould. The microstructure of the cast samples was characterized by optical and scanning electron microscopy and energy dispersive spectrometry. Ultrasonic vibration promoted the formation of small α-Al globular grains, changed the size and morphology of intermetallic compounds and distributed them uniformly throughout the castings. Ultimate tensile strength and strain were increased to 332 MPa and 2.9%, respectively, which are 50% and 480% higher than the values obtained for castings produced without vibration. The microstructure morphology and the alloy mechanical properties were found to depend on the electric power and the melt temperature, and by using a suitable combination of these parameters it is possible to achieve high refinement efficiency by treating the melts in the liquid state.     

Effect of Cu on microstructure and mechanical properties of 2519 aluminum alloy

The effect of Cu on the microstructure and mechanical properties of 2519 aluminum alloy was investigated by means of tensile test, microhardness test, transmission electron microscopy, and scanning electron microscopy. The results show that when the content of Cu is less than 6.0%, the strength of 2519 aluminum alloy increases with the increase of Cu eontent; when the content of Cu is more than 6.0%, the strength of the alloy decreases. The hardening effect of the aged alloy is accelerated at 180℃ and the time to peak age is reduced, but the plasticity of the alloy gradually decreases with the increase of Cu content. However, the hardening effect of the aged alloy decreases with the increase of Cu as the content of Cu is over 6.0%. The optimal content of Cu of 2519 aluminum alloy is 6.0%, at which the alloy has best tensile strength and plasticity.