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研究了采用不同焊接工艺参数时铸造Al Si14高硅铝合金搅拌摩擦焊接头的微观组织、力学性能及断口形貌。结果表明,焊核区组织由于发生动态再结晶,晶粒非常细小;热力影响区紧靠焊核区,在较高转速时出现被拉长的组织;热影响区基体α相及共晶Si晶粒尺寸相对于母材均有所增加。在搅拌头转速为1 300 r/min、焊速为100 mm/min时,获得的接头抗拉强度可达到母材的92%;断裂发生在前进侧热影响区,断裂方式是韧性与脆性的混合型断裂;接头显微硬度近似呈"马鞍"形分布,在热力影响区附近硬度低于母材硬度。 相似文献
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《热加工工艺》2020,(9)
对异种材料6061铝合金和Al Si12合金进行搅拌摩擦焊接试验,探究了6061/AlSi12异种材料搅拌摩擦焊接接头的组织与不同焊接速度对力学性能影响。结果表明:经拌摩擦焊接后,焊核区域由于受到搅拌针强烈的搅拌作用和摩擦作用,受到较高温度的热循环,使得6061晶粒发生再结晶,晶粒细化,块状Si发生缩颈、熔断并粒化,弥散分布在基体上,从而提高接头强度;当焊接速度为400 mm/min时,接头的抗拉强度达到最大175.93 MPa,是6061母材的70%,是Al Si12母材的90%;接头焊缝断面的横向微观硬度分布呈现"阶跃"式,当焊接速度为200 mm/min时,焊核区域的硬度最大。 相似文献
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《特种铸造及有色合金》2018,(11)
研究了不同进给速度对AZ31B镁合金/5052铝合金铜界面合金化搅拌摩擦焊焊接接头组织与性能的影响。结果表明,在进给速度为200mm/min时接头的抗拉强度最低,在进给速度为100mm/min和300mm/min时焊缝的抗拉强度较好;随着添加铜箔的厚度增加,焊接接头的抗拉强度先增加后降低。在进给速度为100mm/min,铜箔厚度为0.05mm,旋转速度为1 200r/min时能得到良好的焊接接头,其最大抗拉强度为87.5 MPa;加入铜箔后,接头处生成了Mg_2Al_3、Mg_(17)Al_(12)、AlCu、Al_2Cu、MgCu_2相,无明显焊接缺陷,硬度分布近似成"M"形。 相似文献
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《金属学报》2017,(12)
采用高转速微型搅拌摩擦焊接工艺实现了0.8 mm厚6061-T6铝合金薄板对接。利用OM、SEM、TEM及EBSD等测试技术探讨了高转速对接头微观组织及力学性能的影响规律。结果表明,高转速焊接6061-T6薄板时,焊缝表面成型良好,焊缝各区域组织呈连续均匀过渡。与常规搅拌摩擦焊相比,高转速工艺下,焊缝区b-Mg2Si、S相(Al2Cu Mg)和Al8Fe2Si析出相数量增多,特别是长条状b-Mg_2Si数量增多,焊缝区显微硬度值明显提升;转速8000 r/min、焊速1500 mm/min条件下,接头最大抗拉强度高达301.8 MPa,是母材抗拉强度(351.7 MPa)的85.8%;转速对6061-T6铝合金超薄板高转速搅拌摩擦焊对接接头抗拉强度影响较小,接头断裂模式为脆性断裂为主的韧-脆混合断裂。 相似文献
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以0.8 mm厚6061铝合金微搅拌摩擦焊对接过程为研究对象,采用专用搅拌工具,通过温度场模拟进行工艺参数预选,研究了无倾角微搅拌摩擦焊的工艺参数对接头力学性能的影响,确定了与所设计微搅拌工具相匹配的工艺参数窗口;并采用光学显微镜、SEM扫描电镜对接头的微观组织、断口的形貌进行观察. 结果表明,在焊接速度为300 mm/min、转速14 000 ~ 24 000 r/min时,可以获得力学性能优越的焊接接头,抗拉强度均可达母材的70%以上;微搅拌摩擦焊缝微观组织的热影响区与传统搅拌摩擦焊相比,仅部分晶粒发生长大,仍有部分晶粒与基体保持一致无明显变化. 相似文献
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AbstractUsing a recently developed hot cracking test, the cracking susceptibilities of the high-strength aluminium alloys 7010 and 7050 were investigated. The solidification conditions in the test are similar to those encountered in the ingot shell zone during semi-continuous direct chill casting. The influence of grain structure on cracking susceptibility was investigated. Al-Ti and Al-Ti-B grain refining master alloys were added to the melt at various levels in order to obtain grain structures ranging from columnar-dendritic to equiaxed-cellular. Without grain- refiner additions, columnar structures formed which had high cracking susceptibilities; 7010 being marginally less susceptible than 7050. With high grain-refiner additions, equiaxed-cellular grains formed in both alloys, again leading to high cracking susceptibility. Equiaxed-dendritic grains formed at moderate addition levels of grain refiner and were found to be more resistant to hot cracking than either of the other morphologies. 相似文献
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本文提出了一种新的铝合金重力铸造简易模具设计方法,兼具砂型铸造和金属型铸造的优点,提高了铸件的质量和生产效率,又明显地降低了生产成本。 相似文献
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This work aims to reveal the relationships between the microstructure,mechanical properties and flow behavior of die-casting AlMg_5Si_2Mn alloy.Results indicated that the microstructure of the die-cast AlMg_5Si_2Mn consists of α_1-Al grains,fine-size α_2~Al grains and(Al +Mg_2Si) eutectic.The surface layer observed has the thickness in a range of120-135 μm,while an ellipse-like surface layer edge is observed in the corner of the plate-like sample.Tensile strength and elongation(5) of the specimens are slightly decreased along the die-filling direction due to the backflow of melt.Pure(Al + Mg_2Si) eutectic layer and ultra-fine-size α_2-Al grains observed are around the overflow channels.Mass feeding is predominantly responsible for the superior mechanical properties of the round bars as compared to those of plate-like samples. 相似文献