高强度锌铝合金齿轮挤压铸造成形

介绍了用挤压铸造技术制造高强度锌铝合金齿轮特别是有防爆、阻燃要求的齿轮的方法.挤压铸造高强度锌铝合金齿轮模具结构、制造工艺简便可靠,生产成本低,经济效益高.     

陶瓷粒子增强的锌铝基复合材料的摩擦学特性

以陶瓷颗粒碳化硅、氮化硅、三氧化二铝为增强体，锌铝合金ZA-27为基体，通过对陶瓷颗粒进行预处理、机械搅拌和合金化等技术，将陶瓷颗粒与熔融状态的锌铝合金复合成均匀的浆料，用挤压铸造法挤压成型，得到陶瓷颗粒锌铝合金复合材料铸件。在金属基体上，均匀分布着陶瓷颗粒。在有润滑和无润滑的情况下，复合材料的耐磨减摩性能均比ZA-27有较大幅度提高。     

铝合金轮毂浮动阴模挤压铸造工艺研究

在铝合金轮毂结构工艺性分析的基础上,针对直接冲头挤压铸造的铝合金轮毂易出现缩孔和缩松等缺陷的问题,对挤压铸造工艺过程进行了试验研究。结果表明,采用浮动阴模挤压铸造工艺制造可避免铝合金轮毂缩孔和缩松等缺陷。     

高铝锌基合金直齿圆锥齿轮的挤压铸造工艺

利用挤压铸造技术生产高铝锌基合金直齿圆锥齿轮，齿面精度能够得到保证。适用于工作环境较好，载荷不是很大条件下的高铝锌基合金直齿圆锥齿轮，可减少设备投资、减少工序工时，从而大大降低生产成本，具有很高的经济效益和社会效益。     

7050铝合金的真空压铸

7050铝合金是一种优秀的高强度铝合金,其各种半成品如板材、挤压材、锻件等在航空航天器制造中获得了广泛的应用,然而由于铸造性能差,其铸件未能得到应用。美国豪梅特研究公司(Howmet Research C0rp.)J.’r.斯特里(Staley)采用真空压铸法翩得了显微组织与性能良好的7050铝合金铸件,扩大了合金的应用范围。7050铝合金的真空压铸@王祝堂~~     

浇注温度对铝合金制动泵体流变挤压铸造的影响

高强度铝合金代替钢铁零件已成为汽车轻量化的一个重要发展方向。半固态流变挤压铸造生产的铸件,成品率高、力学性能好,有着广阔的发展空间。使用半固态流变挤压铸造工艺生产了汽车铝合金制动泵体,并通过金相实验和拉伸实验研究了浇注温度对铝合金制动泵体流变挤压铸造的影响。结果表明,在600~620℃浇注可获得金相组织呈近球状的制动泵体,且质量良好;随着浇注温度降低,铸件的晶粒尺寸变小,抗拉强度和伸长率增大。     

汽车发动机支架的挤压铸造工艺开发

汽车发动机支架有特殊的产品要求,根据铝合金液态间接挤压铸造的工艺特点,设计了汽车发动机支架制造工艺流程,在铸件设计、挤压铸造模具开发和挤压铸造生产过程控制中解决了一系列关键问题.     

工艺参数对ADC12铝合金连杆端盖挤压铸造过程的影响

利用挤压铸造工艺制造了ADC12铝合金连杆端盖零件,分析了浇注温度和比压对挤压铸造零件力学性能的影响。结果表明,采用挤压铸造工艺可以成功地制造出具有较高的表面品质和力学性能的ADC12铝合金连杆端盖零件。浇注温度和比压对挤压铸造连杆端盖的力学性能有着较大影响,最佳的浇注温度和比压分别为700℃和250MPa,此时其抗拉强度达到366MPa,伸长率达到6.5%。     

锌、铝合金模具简易铸造法

本文介绍了一种用硅橡胶复制石膏型(芯)来浇注各类形状复杂、精度高、表面光洁的锌,铝合金模具简易铸造法。可用于吹塑、注塑、橡胶硫化等锌、铝合金模的生产,及高强度锌合金冲压模的生产。     

基于数值模拟的铝合金汽车行李箱盖内板挤压铸造

铝合金大型薄壁铸件成型过程中充型困难,容易出现浇不足、冷隔等缺陷。基于数值模拟,采用ADC12铝合金对国内某款汽车行李箱盖内板开展直接挤压铸造研究,确定了合理的挤压铸造工艺参数,制造了模具并成功试制了铝合金汽车盖内板样件。     

炉料搭配和均匀化处理对铸造锌铝合金组织与性能的影响

采用扫描电子显微镜和能谱微区分析,研究了以全新炉料和新旧炉料两种不同炉料搭配方式生产铸造锌铝合金铸件的组织与性能,并对其在铸态和经均匀化处理后的显微组织及成分进行了对比分析。发现采用全新炉料搭配比采用新旧炉料按1∶1搭配的铸造锌铝合金显微组织均匀、力学性能好;在相同条件下,经均匀化处理比铸造状态下的综合性能好。     

A comparative study on Sn macrosegregation behavior of ternary Al-Sn-Cu alloys prepared by gravity casting and squeeze casting

A comprehensive study on Sn macrosegregation behavior in ternary Al-Sn-Cu alloys was carried out by comparative analysis between gravity casting and squeeze casting samples. The microstructure and Sn distribution of the castings were characterized by metallography, scanning electron microscopy(SEM), energy-dispersive X-ray(EDX) spectroscopy, and a direct reading spectrometer. Results show that there are obvious differences in Sn morphology between gravity casting and squeeze casting alloys. Unde...     

Research progress on squeeze casting in China

Squeeze casting is a technology with short route,high efficiency and precise forming,possessing features of casting and plastic processing.It is widely used to produce high performance metallic structural parts.As energy conservation and environmental protection concerns have risen,lightweight and high performance metal parts are urgently needed,which accelerated the development of squeeze casting technology over the past two decades in China.In this paper,research progress on squeeze casting alloys,typical parts manufacturing and development of squeeze casting equipment in China are introduced.The future trend and development priorities of squeeze casting are discussed.     

流变挤压铸造制备LPSO结构增强Mg-Zn-Y-Zr合金及其组织性能

采用流变挤压铸造工艺制备了含有LPSO结构的Mg99.9-3xZnxY2xZr0.1(x=0.5、1、2,摩尔分数,%)合金,研究了合金的微观组织特征及力学性能。结果表明,流变挤压铸造能有效细化合金的微观组织。合金的基体组织由尺寸较大的α1-Mg和尺寸较小的α2-Mg晶粒组成,LPSO结构呈细小的网状结构均匀地分布在晶界处,LPSO结构的含量越低,其细化效果越明显。随着挤压压力增大,合金中LPSO结构的厚度越来越小,当压力达到100MPa后,厚度变化趋缓。与常规重力铸造相比,流变挤压铸造能有效提高合金的力学性能,特别是伸长率。在400MPa下的流变挤压铸造Mg96.9Zn1Y2Zr0.1合金的抗拉强度和伸长率较重力铸造下分别提高了19%和170%。     

The effect of casting temperature on the properties of squeeze cast aluminium and zinc alloys

Gravity casting and squeeze casting were carried out on an aluminium alloy with 13.5% silicon and a zinc alloy with 4.6% aluminium with different temperatures, 660, 690 and 720 °C for the former and 440, 460 and 480 °C for the latter. A top-loading crucible furnace was used to melt the alloys. The die-preheat temperatures used were 200–220 °C for the aluminium alloy and 150–165 °C for the zinc alloy. A K-type thermocouples with digital indicator were used to measure the die surface temperature and the molten metal temperature; while a 25 t hydraulic press with a die-set containing a steel mould was used to perform the squeeze casting with a pressure of 62 MPa. Tensile, impact and density tests were carried out on the specimens. It was found that casting temperature had an effect on the mechanical properties of both gravity cast and squeeze cast aluminium and zinc alloys. The best temperatures to gravity cast the aluminium alloy and the zinc alloy were 720 and 460 °C, respectively. For the squeeze casting of the aluminium alloy, the best temperature to use was either 690 or 660 °C; the former would give a better property at the top of the casting while the latter, at the bottom of the casting. However, for the squeeze casting of the zinc alloy, the best temperature was again 460 °C.     

第四届亚洲铸造大会特铸及有色合金部分论文简介

有选择地介绍了第四届亚洲铸造大会部分论文内容，涉及Ａｌ－Ｓｉ合金变质处理、铝合金晶粒细化处理新发现，Ａｌ－Ｓｉ－Ｍｇ合金裂纹源的新观点，铁对铝铸件形成孔洞的新论点，预测壳芯发气量的新技术，挤压铸造工艺新发展及新型阻燃型镁合金材料等。     

Squeeze casting of aluminium alloys for higher formability in cold forging

Abstract

This research project investigated the process conditions of using squeeze casting process to produce aluminium alloy preforms or billets for subsequent cold forging process. The comparative effects of heat treatments, their microstructures and mechanical properties were evaluated. Through these studies and experiments, the main emphasis is on the study of commercial material Al 6061, Al 2014 and Al 356 alloys. The formability of the alloys was carried out using forward and backward extrusion test at 50% area reduction at room temperature (cold extrusion). It was found that when wrought aluminium 6061, 2014 and 356 alloys were squeeze cast to form the preforms, the preform microstructures revealed very fine microstructures that are feasible to be cold extruded. In addition, after thermal annealing treatment of 6061 squeeze cast preforms, the samples showed a similar value of work hardening exponent value of 0˙20 as compared to the wrought aluminium alloy 6061, with a workhardening exponent value of 0˙21 obtained from the static compression test. Wrought aluminium alloys generally cost twice the amount as compared with casting ingots. The microstructures of the squeeze cast 6061 alloy showed no visible cracks or inclusions after the deformation by extrusion. The results of the studies showed that Al 6061 preforms via squeeze cast technique may be cold extruded or formed, which provide an alternative means for the production of billets for the cold extrusion or forging process.     

Effects of silicon,magnesium and strontium content on the qualities of Al-Si-Mg alloys

According to the specification of AA standard, the magnesium content of 356.1 alloy ranges from 0.25 to 0.45%. In producing Al-Si-Mg alloy the strontium content for the modified 356 (Al-7%Mg) alloy might range from 0.005 to 0.02%. Therefore, 356 alloys might be produced with different percentages of Mg and/or Sr. The effects of changes in Si content (from 6.6% to 10.8% in gravity casting and 6.5% to 10.3% in squeeze casting), Mg content (from 0.36% to 0.48% in gravity casting and 0.3% to 0.44% in squeeze casting), and Sr content (from 0.0007% to 0.0158% in gravity casting and 0.0015% to 0.04% in squeeze casting) on the microstructures, density, mechanical properties and strength of different Al-Si-Mg alloys were fully investigated and discussed. Different melts were poured in the ASTM B108 permanent mould and dies in a vertical squeeze machine to produce bar castings. These bar castings were then machined and the mechanical properties tested. Experimental results showed that if a high strength and a high elongation were desired in a squeeze casting after T6 treatment, an increase in Si and Sr content to 9.9% and 0.019% (Mg at 0.3%) would lead to 280 MPa strength, 12% elongation and Weibull modulus of 34 in reliability of strength. If both strength and reliability were desired in a squeeze casting after T6 treatment, an increase in Si content to 10.3% (Sr at 0.0015% and Mg at 0.3%) would result in 294 MPa strength, 8.7% elongation and a great Weibull modulus of 67. In gravity casting, after T6 treatment, increasing Si content to 10.4–10.55% and Sr content in the range of 0.0007–0.0208% and 0.35% Mg could develop 282–284 MPa strength at about 6.6% elongation with Weibull modulus of around 31. In Al-7Si-Mg alloy, increasing Mg content from 0.26% to 0.48% decreased the tested elongations of both as-cast and heat treated squeeze castings and gravity castings.     

Influence of Applied Pressure on Tensile Behaviour and Microstructure of Squeeze Cast Mg Alloy AM50 with Ca Addition

The development of alternative manufacturing processes is essential for the success in applying Ca-containing magnesium alloys for automotive applications due to their relatively poor die castability. Squeeze casting with its inherent advantages has been demonstrated capable of minimizing the formation of casting defects in Mg-Al-Ca alloys. In this study, the effect of applied pressures on tensile behavior and microstructure of squeeze cast Mg-5wt.%Al-1%wt.%Ca alloy (AMX501) was investigated with the applied pressure varying from 3 to 90 MPa. The results of tensile testing indicate that the tensile properties of AMX501 alloy including ultimate tensile strength, yield strength, and elongation (E _f) increase from 153.7, 80 MPa and 3.26% to 183.7, 90.5, and 5.42% with increasing applied pressure levels from 3 to 90 MPa, respectively. The analysis of true stress versus strain curves shows that an increase in applied pressure levels result in high straining hardening rates during the plastic deformation of the alloy. Microstructural analysis and density measurements indicate that, as the applied pressure increases, the porosity levels of the alloy decrease considerably, despite of almost no significant reduction in grain sizes of the squeeze cast alloys due to their high aspect ratio of cylindrical castings. Hence, the improvement in tensile properties should be primarily attributed to casting densification resulting from applied pressures. The scanning electron microscopy observation on fractured surfaces reveals that the fracture modes of the squeeze cast alloys transit to ductile from brittle with increasing applied pressures.     

Section thickness-dependent tensile properties of squeeze cast magnesium alloy AM60

The development of alternative casting processes is essential for the high demand of light weight magnesium components to be used in the automotive industry,which often contain different section thickn...