热处理对开孔泡沫Al-Mg-Si合金性能的影响

研究热处理对渗流法生产的开孔泡沫AlMgSi合金在动态(～2.1×103s-1)和准静态(1.0×10-3s-1)加载条件下压缩力学性能及能量吸收特性的影响。分别在MTS810材料试验机和分离式Hopkinson压杆(SHPB)上对泡沫铝合金材料在加工态(F)、时效处理(A)和固溶处理加时效(T6)三种状态下进行了单向压缩实验。结果表明:与加工态下相比,经时效硬化及T6强化的泡沫铝合金的动态和静态压缩强度提高、平台区缩短,而且均表现出对应变率的敏感性。尤其值得注意的是纯时效硬化与T6强化相比,不经固溶处理就可达到提高平台应力及单位体积能量吸收量的目的,是一种值得推广的泡沫铝合金强化处理方法。     

Compressive properties and energy absorption characteristics of open-cell nickel foams

Open-cell nickel foams with different relative densities and pre-stretching degrees were subjected to room temperature quasi-static compressive tests to explore their compressive properties. The compressive properties of the nickel foams including yield strength, elastic modulus, energy absorption density and energy absorption efficiency were calculated accurately. The results show that the compressive properties of yield strength, elastic modulus and energy absorption density increase with the increase of relative density of nickel foams. The compressive properties are sensitive to the pre-stretching degree, and the values of yield strength, elastic modulus and energy absorption density decrease with the increase of pre-stretching degree. However, the energy absorption efficiency at the densification strain state exhibits the independence of relative density and pre-stretching degree. The value of energy absorption efficiency reaches its peak when the strain is at the end of the collapse plateau region.     

Fabrication and compressive behavior of open-cell aluminum foams via infiltration casting using spherical CaCl2 space-holders

The infiltration casting fabrication process based on spherical CaCl₂ space-holders and the compressive behavior including the mechanical performance and energy absorption capacity of open-cell aluminum foams were investigated.Open-cell aluminum foams with different porosities in the range of 63.1%to 87.3%can be fabricated by adjusting compression ratios of CaCl₂ preforms prepared by precision hot-pressing.The compression tests show that a strain-hardening phenomenon always occurs especially for open-cell aluminum foam with low porosity,resulting in the inclining stress-strain curve in the plateau region.The energy absorption capacity of open-cell aluminum foam decreases with increasing porosity when compared at the same strain.However,when compared at a given stress,each foam can absorb the maximal energy among the five foams in a special stress range.Additionally,open-cell aluminum foam possesses the maximum energy absorption efficiency at its optimum operating stress.At this stress condition,the foam can absorb the highest energy compared with other foams at the same stress point.The optimum operating stress and the corresponding maximal energy absorption decrease with increasing the porosity.The optimum operating stress for energy absorption can also be determined similarly when taking into consideration of the lightweight extent of foams.     

Sound absorption property of open-pore aluminum foams

The sound absorption property of aluminum foam was studied by testing its sound absorption coefficients using standing wave tube method. The open-pore aluminum foams were prepared by infiltration process, with pore size of 0.5 mm to 3.2 mm and porosity of 54.2% to 77%. The frequency of indicted sound wave was ranging from 125 Hz to 10 kHz. The results show that the average values of sound absorption coefficients are all over 0.4 and the aluminum foam has better sound absorption property, its coefficients is influenced by frequency and pore structure, and reaches the maximum at about 1 kHz, with increasing porosity and decreasing cell diameter the sound absorption coefficient values increase.     

Sound absorption property of open-pore aluminum foams

This paper presents a study on sound absorption property of aluminum foam by evaluating its sound absorption coefficients using standing wave tube method. Experimental results showed that the average values of sound absorption coefficients (over the test frequency range) are all above 0.4, which indicate very good sound absorption property of the aluminum foams. The sound absorption coefficient is affected by frequency and pore structure, and reaches its maximum value at around 1 000 Hz. With the increase of porosity and decrease of cell diameter, the sound absorption coefficient values increase.     

Mechanical properties and energy absorption properties of aluminum foam-filled square tubes

Longitudinal and transverse mechanical properties and energy absorption properties of foam-filled square tubes under quasi-static loading conditions were studied. The foam-filled thin-walled square tube was fabricated with aluminum tube as its shell and closed-cell Al-Mg alloy foam as its core. The results indicated that the plateau region of the load-displacement curve exhibited a marked fluctuant serration which was clearly related to the formation of folds. The longitudinal deforming mode of foam-filled square tube was the same as that of the empty tube, but the fold number of foam-filled square tube was more than that of the empty tube. The longitudinal compression load and energy absorption value of foam-filled square tube were higher than the sum of that of aluminum foam (alone) and empty tube (alone) due to the interaction between tube and filler. In transverse direction, the compression load and energy absorption ability of foam-filled square tubes were significantly lower than those in longitudinal direction.     

Compressive properties of aluminum foams by gas injection method

The compressive properties of aluminum foams by gas injection method are investigated under both quasi-static and dynamic compressive loads in this paper.The experimental results indicate that the defo...     

开孔泡沫铝材料静态压缩力学性能与吸能特性

实验研究了开孔泡沫铝材料静动态压缩过程的力学性能和吸能特性.得到了材料在静态压缩下(1.0×10-3s-1)的微观变形特点.用单位体积的吸能W来表征材料的吸能特性,分析了在静态条件下孔径和材料叠加对泡沫铝材料的应力-应变关系和单位体积吸能的影响规律.     

6005A铝合金挤压型材热处理工艺研究

研究了地铁列车车体用6005A铝合金挤压型材热处理工艺对其力学性能的影响。结果表明,6005A挤压型材的过烧敏感温度在590℃～600℃之间;壁厚5 mm的6005A铝合金挤压型材在(520℃～570℃)2 h范围进行固溶,材料的综合性能良好。560℃2 h固溶时,综合性能最佳;随时效温度的升高,时效强化的速率加快,达到最大强化效果所需的时间越短,最终获得的强度越低;时效制度为175℃10 h时,强化效果最好;固溶水冷后时效的延迟时间应控制在3 h以内或48 h之后,该合金挤压型材才能达到良好的强化效果。     

Compressive properties and energy absorption of aluminum foams with modified cellular geometry

This study presents experimental results on the behavior of aluminum alloy metal foams with controlled pore morphology in compression. Two types of metal foams were analyzed, having uniform cell structure and with a dual-size cell arrangement seeking optimized mechanical properties. The structures were manufactured by lost-wax casting using 3D printed components for internal structure definition. Results for stiffness and energy absorption were obtained and compared on weight efficiency basis. The results are indicative of higher efficiency of the dual-size structures that may be considered for use in components subjected to impact or compression loading.     

热处理制度对2519铝合金板材力学性能和应力腐蚀敏感性的影响

选用3种不同的热处理工艺对2519铝合金板材进行处理，采用测定试样在腐蚀前后力学性能的变化即腐蚀的力学性能指标Kσ和Kδ来评定2519铝合金的应力腐蚀敏感性。结果表明：2519铝合金板材经先高温后低温的双级时效处理(180℃，3h 145℃，24h)后力学性能最好，抗应力腐蚀性能最差；而经形变热处理(20℃，100h 冷加工15％ 145℃，21h)后的力学性能较好，抗应力腐蚀性能最好；过时效状态(180℃，30h)下力学性能最差，抗应力腐蚀性能适中。     

热处理工艺对6061铝合金筒形件旋压过程及其性能影响

为满足某6061铝合金筒形件产品较高的形状、尺寸精度及机械性能要求,对热挤压态6061铝合金管坯件旋前不同热处理工艺规范(退火、固溶、不完全退火和半同溶)进行了分析比较,研究获得不同热处理工艺规范对旋压成形过程及其性能的影响规律.结果表明,对热挤压态6061铝合金管坯件而言,在旋压成形前进行半固溶处理(即将管坯加热到4...     

Compressive deformation behavior and energy absorption characteristic of aluminum foam with elastic filler

An open-cell aluminum foam filled with silicate rubber (AFFSR) was fabricated by infiltration of the liquid silicate rubber into the open-cell aluminum foam. The experiments were carried out to investigate the compressive behavior and energy absorption characteristics of the material. It is found that the stress--strain response of the AFFSR exhibits five regions including two plateau regimes, which is quite different from the stress--strain curves of many unfilled metallic foams that usually exhibit three distinct regions. The plastic deformation of the AFFSR is prolonged because of the filled silicate rubber, compared with the aluminum foam without such a filler. The AFFSR also exhibits a higher energy capacity than the aluminum foam without filler. Additionally, for the prolonged plateau region in the stress--strain curve, the energy absorption efficiency of the AFFSR maintains a high level (above 0.6) over a wide strain range from 3% to 60%.     

热处理对喷射成形7xxx系铝合金TIG焊接头组织与性能的影响

采用7055焊丝对喷射成形7xxx系铝合金进行TIG焊接,接头经450℃×1 h＋475℃×1 h的双级固溶后水淬,再进行120℃×24 h的时效处理后,焊缝组织均匀、晶粒有所长大,但没有出现过烧现象.经复合固溶处理后合金元素充分溶入基体,使得基体中的合金元素含量高于固溶前的含量,而固溶之前分布在晶界的合金元素经固溶之后降低了,固溶过程使合金成分区域趋于均匀化,后续的时效过程中过饱和固溶体析出强化相,使得接头强度得到了显著提高7,055达到了母材强度的65%,7475达到了母材强度的91%.结果表明,试验拟定的热处理工艺是合理的.     

胞状AlCu5Mn合金泡沫的压缩性能和能量吸收特性

用熔体发泡法制备孔隙率为51.5%～90.5%、孔结构均匀的胞状铝合金(AlCu5Mn),研究其孔结构、压缩性能、能量吸收能力、能量吸收效率和吸能性能.结果表明:胞状铝合金孔结构由高孔隙率(88.8%)时的大孔径、多边形孔向低孔隙率(62.5%)时的小孔径、球形孔孔结构过渡,其压缩应力(σ)-应变(ε)曲线具有线性变形阶段、屈服平台阶段和致密化阶段三个部分,由线性变形阶段进入屈服平台阶段所对应的ε_s值介于2%～9%之间;屈服强度σ_s~*随着孔隙率的增大而下降,在孔隙率相同的条件下,胞状铝合金的力学性能优于胞状铝和多孔铝合金,其比刚度高于钢;当应变为定值时,胞状铝合金单位体积和单位质量的压缩吸能能力(C和C_m)都随着孔隙率的升高而降低,但是孔隙率在73.5%～82.1%范围内时,其C_m与ε的关系几乎不随孔隙率的改变而改变;对于孔隙率为51.5%～90.5%的胞状铝合金,它们的吸能效率的峰值都大于80%.胞状铝合金的C-σ和C_m-σ关系可以表征其吸能性能,从而可以根据实际工况选择作为减振吸能材料的胞状铝合金的最佳孔结构.     

Damping capacity and compressive characteristic in some aluminum foams

1　INTRODUCTIONMetallicfoams ,especiallyaluminumalloyfoamsaresuper lightmetalsexhibitingunique propertiessuchashighenergyabsorptionandhighdampingca pacity .So ,theyarebelievedtohavegreatpotentialforapplicationsinmanyaspects ,forexample ,theap plicationinenergyabsorptionandvibrationdamping .Therefore ,theirmechanicalpropertieshaveattractedaconsiderableattentioninrecentyears .Anumberofworksonthecompressivebehavioroffoamedalu minumanditsalloyhaverevealedthatthedeforma tionbehaviorofaluminumf…     

余热热处理对Al-Si-Cu合金铸件组织和性能的影响

研究了余热热处理工艺对Al-Si-Cu合金中Cu元素的固溶效果、共晶Si颗粒形貌及尺寸变化、以及该工艺对合金铸件力学性能的影响.结果表明,余热热处理工艺条件下,铸件可以在更短的时间内获得理想的固溶效果.通过分析铸件微观组织显微可知,余热热处理工艺可以通过缩短固溶处理时间有效地抑制共晶Si颗粒的粗化,在4h的固溶处理中Si颗粒平均尺寸持续减小且未出现粗化趋势.采用相同工艺参数,余热热处理工艺条件下制备的单铸试棒抗拉强度比传统T6热处理工艺提升约15%.     

热处理对高强铝合金搅拌摩擦焊接头热力影响区组织和性能的影响

分析讨论了热处理对高强铝合金热力影响区的组织和力学性能的影响.结果表明,经热处理后,热力影响区的棒状沉淀相逐渐消失,球状沉淀相弥散分布在热力影响区的晶界和晶粒中.两种铝合金在热处理后力学性能上都有一定的提高,7075铝合金接头的抗拉强度可达415 MPa,是母材抗拉强度的89.5%,7050铝合金接头的抗拉强度可达422 MPa,是母材抗拉强度的89.8%,断裂几乎都发生在前进侧的热力影响区,并且硬度的最低处在前进侧热力影响区.     

热处理对含Ag耐热铝合金组织与性能影响

通过铸锭冶金及形变热处理,制备了一种含0.6Ag的Al-5.3Cu-0.8Mg-0.6Mn耐热铝合金.采用光学显微镜、扫描电子显微镜、差热分析及力学性能测试,研究了热处理工艺(包括均匀化处理、固溶及人工时效处理)对合金的组织与性能影响,并推导了其均匀化动力学过程.结果表明,理想的热处理工艺是均匀化制度为500℃×12h,固溶温度为525℃,人工时效制度为185℃×8h.通过优化热处理工艺,合金的室温抗拉强度达570MPa,伸长率在10%以上.