颗粒增强Al-20Si-5Mg合金气缸套与铸铁气缸套的性能比较

通过对铸态、固溶态和固溶+时效态的颗粒增强Al-20Si-5Mg合金复合材料离心铸造气缸套,以及汽车、摩托车铸铁气缸套进行硬度(HRB)、不同工况下耐磨性测试分析和显微组织观察.结果表明,颗粒增强Al-20Si-5Mg合金复合材料气缸套的平均硬度比灰铸铁气缸套的平均硬度低;随着外加载荷的增加,颗粒增强过共晶铝硅合金复合材料气缸套耐磨层中,干摩擦条件下铸态、固溶态及时效态的耐磨性能明显优于铸铁气缸套,湿摩擦条件下,在高载荷(300和400 N)时,铸态、固溶态及时效态耐磨性能略优于铸铁气缸套.     

T6态Al-20Si-5Cu合金干滑动摩擦磨损特性研究

以T6态Al-20Si-5Cu合金为研究对象,采用UMT-2型摩擦磨损试验机研究材料的摩擦磨损性能,并用SEM、EDS、奥林巴斯激光共焦扫描显微镜OLS4000分析材料的常温摩擦磨损行为。结果表明:Al-20Si-5Cu合金的磨损率随着附加载荷的增加而增大,但在高载荷下磨损率仍然很小,表现出了良好的耐磨性;摩擦系数平均值在0.38~0.42范围内变化,且在磨损过程中随时间的变化不大,表现出了较强的稳定性;同时,随着载荷的增大,材料的磨损机制发生改变,由低载荷的氧化磨损、磨粒磨损转变为疲劳磨损。     

汽车发动机用铝硅合金的半固态成形工艺

采用斜坡法制备了Al-20Si-3Fe合金坯料,并对合金坯料进行二次加热、触变成形和固溶时效处理,研究了二次加热温度和保温时间对半固态合金坯料组织的影响,并对比分析了触变成形和固溶时效处理对合金组织与性能的影响。研究结果表明, Al-20Si-3Fe合金适宜的二次加热工艺为：加热温度580℃,保温30 min;3种状态下合金的强度和硬度顺序从高到低依次为：热处理态>触变成形>铸态,其中,热处理态和触变成形态合金的塑性相当,且都高于铸态合金。     

过共晶铝硅合金的摩擦磨损性能研究

采用P-Cu和Al-RE中间合金对过共晶Al-20Si合金进行变质处理,在观察显微组织的基础上对Al-20Si铝硅合金进行了摩擦磨损特性研究.结果表明,铸态Al-20Si合金经变质和T6热处理后,磨损失重量减少了26%～42%,摩擦因数减小了8%～11%,其耐磨性能得到明显改善.合金耐磨性能的改善与复合变质引起的共晶硅和初晶硅颗粒的细化及热处理使得合金的强度进一步提高有关.合金变质前的磨损机制主要为磨粒磨损和粘着磨损,变质后的合金磨损机制明显为磨粒磨损.     

Zn含量对Al-12Si-3Cu合金强度和磨损性能的影响（英文）

系统研究Zn含量对重力铸造Al-12Si-3Cu合金强度和磨损性能的影响。通过OM、XRD、SEM、硬度、拉伸、压缩和Charpy冲击测试等手段对合金的显微组织和力学性能进行评价。干滑动磨损测试采用球-盘式摩擦磨损仪。显微镜观察结果显示,基体显微组织含有α(Al)枝晶、针状和粗Si颗粒及CuAl_2 (θ)相。添加Zn导致合金中α-固溶体的形成和粗Si颗粒含量的增加。随着Zn含量的增加,Al-12Si-3Cu-Zn合金的硬度、屈服强度、抗拉强度、抗压强度、断裂伸长率和冲击韧性均增加;但是,当Zn含量为1.5%～2%时,合金的抗拉强度、抗压强度和伸长率均降低。此外,Al-12Si-3Cu-Zn合金的摩擦因数和体积磨损量随Zn含量的增加而减小。总之,在Al-12Si-3Cu合金中加入Zn可以提高其作为摩擦材料的应用潜力。     

镁与热处理对Al-4Si-(xMg)合金导电性及力学性能的影响

利用SEM、XRD、EDS、硬度计及电阻率测试仪等方法分析Mg元素和不同热处理对Al-4Si-(xMg)(x=0～1.5％,质量分数)系列合金导电率及硬度的影响.结果表明:随Mg添加量增加,铸态合金的导电率和硬度先增后减,最佳添加量为1.1％.Mg使铸态合金硬度显著增加,但恶化了其导电率.Al-4Si-(xMg)合金经...     

多向强应变和时效处理对Al-Zn-Mg-Cu合金摩擦磨损性能的影响

为探明多向强应变和时效处理对Al-Zn-Mg-Cu合金的显微组织、力学性能和摩擦磨损性能的影响，以多向锻造和时效处理工艺加工Al-Zn-Mg-Cu合金，对其显微组织进行了表征，并对其力学性能和摩擦磨损性能进行了测试。研究结果表明：经多向锻造加工后，Al-Zn-Mg-Cu合金的强度和硬度提高，但伸长率和耐磨性却大幅度下降。锻造合金再经120℃×1320 min时效处理后，强度和硬度进一步提高，伸长率得到明显改善，耐磨性增强。Al-Zn-Mg-Cu合金的抗拉强度、硬度和伸长率分别达到644 MPa、210 HV和14.9%,耐磨性较挤压T6态提高了68.3%。由于高的硬度和加工硬化使耐磨性增强，并且晶界析出相的不连续分布降低了晶界处的应力集中，从而也改善了Al-Zn-Mg-Cu合金的耐磨性。     

元素Cu、Mn及热处理对Al-20Si合金组织及力学性能的影响

在Al-20Si合金中添加含Cu、Mn元素的中间合金,熔炼得到Al-20Si-0.2Cu-0.3Mn、Al-20Si-0.6Cu-0.5Mn、Al-20Si-1Cu-0.7Mn和Al-20Si-1.4Cu-0.9Mn的Al-Si合金。采用金相显微镜、拉伸试验机、布氏硬度计等对铸态及固溶处理+人工时效(T6)热处理态的不同Cu、Mn含量的Al-20Si合金的微观组织及力学性能进行研究。结果表明:Cu、Mn元素可以细化Al-20Si合金中的初生硅和共晶硅,使其组织均匀化,并提高Al-20Si合金的抗拉强度和布氏硬度。Cu、Mn元素的合理添加量分别为1wt%和0.7wt%,此时铸态Al-20Si合金的抗拉强度达到最大值(238 MPa),T6热处理态Al-20Si合金的硬度达到最大值(212 HB)。T6热处理可以改善Al-20Si合金中的Si相,细化初晶硅和共晶硅,消除枝晶,并形成固溶强化。     

热处理工艺提高Al-17Si-5Cu合金的干滑动耐磨性（英文）

通过等温热处理调整铸态Al-17Si-5Cu (AR)合金中Si (尤其是共晶Si)颗粒的形貌以提高合金的耐磨性能。通过销-盘式摩擦机对比研究热处理后的合金(HT合金)和AR合金的磨损行为,并采用扫描电镜观察磨损表面。结果表明,HT合金的显微组织发生显著变化,相应地,HT合金较AR合金的硬度值增大。与AR合金相比,HF合金在所有载荷下总磨损率明显降低,耐磨性能明显改善。热处理后,共晶Si颗粒由针/棒状变为球形/等轴状(长径比接近1),与基体形成良好结合,在磨损过程中保持完整且更加坚硬,为材料提供良好的耐磨性。另外,HT合金硬度的增加进一步提高合金的耐磨性。因此,完整且较硬的Si颗粒对磨损表面的作用以及材料整体硬度的提高导致HT合金在所有载荷下的磨损行为均优于AR合金。     

熔体过热处理对亚共晶Al-10Mg2Si合金磨损性能的影响

对亚共晶Al-10Mg2Si合金进行熔体过热处理,通过削-盘式摩擦磨损试验研究了显微组织对亚共晶Al-10Mg2Si合金磨损性能的影响。结果表明,熔体过热处理后,初生α-Al相转变为近球状等轴晶,Mg2Si相呈纤维状和短杆状均匀分布,且其二次枝晶间距降低了58%,硬度提高了13.5%,同时其磨损速率降低了16.49%。磨屑由合金未经熔体过热处理的推碾薄片状与卷曲状转变为小块粉末状,剥落区面积减小,剥落坑、犁沟和挤压沟槽均变浅。磨损机制由粘着磨损、氧化磨损和磨粒磨损共存转化为以剥层磨损为主,粘着磨损与部分氧化磨损共存的形式,说明熔体过热处理改善了合金的磨损性能。     

液态模锻工艺参数对新型铝合金机械端盖件性能的影响

采用液态模锻工艺,对Al-10Si-0. 8Ti-0. 5In新型铝合金机械端盖件进行了成形,并对不同浇注温度和压力下成形件的耐磨损性能和耐腐蚀性能进行了测试与分析。结果表明:随着浇注温度的升高和压力的增大,试样的磨损体积和单位面积质量损失量先逐渐减小再缓慢增大;与640℃浇注温度相比,680℃浇注时,试样的磨损体积和单位面积质量损失量分别减小了46. 88%和46. 15%;与150 k N压力相比,300 k N压力下,试样的磨损体积和单位面积质量损失量分别减小了48. 88%和53. 33%。Al-10Si-0. 8Ti-0. 5In新型铝合金机械端盖件试样的液态模锻工艺参数优选为:浇注温度为680℃、压力为300 kN。     

Effects of Cu Content on Thermal Stability and Wear Behavior of Al-12.5Si-1.0Mg Alloy

This study investigates how Cu content affects thermal stability and wear behavior of Al-12.5Si-1.0Mg alloy, by adding 2.55 and 4.53 wt.% Cu. The low-Cu and high-Cu alloys were isothermally heat-treated at 300 °C for 100 h. The results indicated that the amount of eutectic Al₂Cu and Al₅Cu₂Mg₈Si₆ particles in the high-Cu alloy was more than that in the low-Cu alloy. These hard particles retained in the Al matrices during isothermal heat treatment, maintaining a relatively stable hardness. Therefore, the hardness of the high-Cu alloy was superior to that of the low-Cu alloy in as-cast condition and after isothermal heat treatment. For wear behavior, both isothermal heat-treated alloys showed the same wear rate with 10 N normal load. The wear rate of Al-12.5Si-1.0Mg alloy was independent on the copper content under 10 N load, but the wear rate at a load of 40 N decreased with increasing Cu content in Al-12.5Si-1.0Mg alloy.     

T6态Al-10Si-5Cu-0.75Mg合金干滑动摩擦磨损性能的研究

利用UMT-2 型摩擦磨损试验机研究了T6态Al-10Si-5Cu-0.75Mg 合金的干滑动摩擦磨损性能,采取SEM、XRD、EDS等方法分析了合金在不同转速和载荷下的摩擦磨损行为。结果表明：合金的磨损率随转速和载荷的增加而增大,但在800 r/min的高转速下仍具有良好的耐磨性,15N高载荷时的磨损率相对于5N低载荷时只增加了291%,属于轻微磨损;摩擦系数的平均值在0.35-0.40范围内变化,且随时间的变化不大,具有较高的稳定性;另外,磨损机制由低速轻载时的磨粒磨损、粘着磨损向高速重载时的剥层磨损、氧化磨损转变。     

热处理对离心铸造自生梯度功能复合材料Al-20Si-5Mg合金的组织性能影响

通过对离心铸造Al-20Si-5Mg合金筒状铸件在不同热处理状态下的硬度和耐磨性能的测定以及显微组织的观察,分析了热处理工艺对合金硬度及耐磨性能的影响.结果表明:铸件内层的硬度在510℃×6h固溶处理后达到最大值HRB90,510℃×6h固溶处理后210℃×12h时效,铸件内层具有最好的耐磨性能.     

TiB2/Al-Si-Mg-Er复合材料的组织与性能

采用重熔稀释法制备了Al-7Si-0.5Mg-0.1Er和0.5TiB₂/Al-7Si-0.5Mg-0.1Er合金,研究了TiB₂颗粒增强Al-Si-Mg-Er复合材料的组织性能。结果表明,复合材料铸态组织主要由α-Al基体、共晶Si相和TiB₂颗粒组成。TiB₂粒子的加入使Al-7Si-0.5Mg-0.1Er合金二次枝晶间距减小了7.1 μm。抗拉强度达到217.53 MPa,较Al-7Si-0.5Mg-0.1Er合金提升了12.1 %。TiB₂/Al-Si-Mg-Er复合材料的最优T6热处理工艺为530 ℃×12 h固溶+160 ℃×7 h时效,经该工艺处理后,TiB₂/Al-Si-Mg-Er复合材料抗拉强度达到319.49 MPa,相比热处理前提高了46.9%,相比Al-7Si-0.5Mg-0.1Er合金提高了5.9%;屈服强度达到266.75 MPa,相比热处理前提高了106.4%,相比Al-7Si-0.5Mg-0.1Er合金提高了14.9%。复合材料抗拉强度的提升主要源于TiB₂颗粒加入后产生的晶粒细化、变质和热处理强化。     

Wear and Friction Behavior of the Spray-Deposited SiCp/Al-20Si-3Cu Functionally Graded Material

The spray-deposited SiCp/Al-20Si-3Cu functionally graded material (FGM) can meet the structure design requirements of brake disk. The effects of rotational speed and load on the wear and friction behaviors of the SiCp/Al-20Si-3Cu FGM sliding against the resin matrix friction material were investigated. For comparison, the wear and friction behaviors of a commercially used cast iron (HT250) brake rotor were also studied. The results indicate that the friction coefficient of the SiCp/Al-20Si-3Cu FGM decreases constantly with the increase of load or rotational speed and is affected by the gradient distribution of SiC particles. The wear rate of the SiCp/Al-20Si-3Cu FGM firstly increases, then decreases and finally increases again with increasing load or speed, and is about 1/10 of that of HT250. Based on observations and analyses on the morphology and substructure of the worn surface, the mechanical mixing layer acts as a protective coating and lubricant, and its thickness reduces with the SiC content increasing. Furthermore, it is proposed that the dominant wear mechanism of SiCp/Al-20Si-3Cu FGM changes from the abrasive wear to the oxidative wear and further to the delamination wear with increasing load or speed.     

The Effect of Ti Addition and Aging on Wear Behavior of AlMgSi Alloys Reinforced with In Situ Al3Ti Particles

The purpose of this study is to investigate the effects of Ti addition (1 and 2% Ti) and aging heat treatment on the mechanical and wear characteristics of Al-12Si-20Mg cast alloys. In preliminary studies conducted to determine the aging parameters, cast alloys were kept at 550 °C for 2 h before being quenched into water and aged at 200 °C for five different periods (3, 6, 9, 12, and 15 h). As the specimen aged for 12 h had the highest hardness value, all the specimens were aged at 200 °C for 12 h. The microstructures of the as-cast and aged specimens were analyzed using an optical microscope and a scanning electron microscope. The hardness of the investigated alloys was measured by micro-hardness test. The wear tests were carried out using the pin-on-disk model wear test apparatus, and the results were evaluated according to weight loss. According to the wear test results, the wear behavior of the investigated alloys changed depending on the aging heat treatment applied and the load. While Ti addition and the aging heat treatment applied reduce the weight loss at low loads (5 N), they increase the weight loss at higher loads (10 and 20 N).