铝硅基精铸材料薄壁壳体成型多尺度分析

针对铝合金薄壁壳体铸造成型高质量要求,通过向ZL101A铝合金中增添Al-10Sr变质剂以及微量Ni元素,制备铝硅基精铸材料坯件,借助加热设备与SCC-44500电子万能试验机对铝硅基精铸材料进行高温压缩试验,得到不同应变率与不同温度下材料的应力-应变曲线,发现铝硅基精铸材料在各应变率及温度下的屈服强度相对ZL101A铝合金均提高。以铝硅基精铸材料进行液压泵薄壁壳体铸造工艺设计分析,基于ProCAST铸造模拟软件,采用低压铸造工艺方案对铝合金薄壁壳体低压铸造过程进行多尺度模拟,分析预测得到了温度场和流动场对铸件充型和凝固过程中缩孔缩松形成的影响,并对壳体铸件的显微组织特征进行了分析,观察得到内部二次枝晶臂间距和共晶层片间距分布状态,综合分析宏微观结果可知,适合的铸造工艺可以制备出完整高性能的铝硅基合金薄壁壳体铸件。     

ZL101A机构箱铸件缩孔缩松缺陷数值模拟分析

针对传统砂型重力铸造制备ZL101A铝合金机构箱铸件普遍存在的缩孔缩松等缺陷,运用华铸CAE软件对该铸件的凝固过程进行了模拟,对初始铸造工艺进行了优化。结果表明:经过液相分布→缩孔形成→Niyama缩松分析后,精确预测了缩孔缩松缺陷产生部位;优化后铸造工艺制备的ZL101A机构箱铸件缩孔缩松较少,且分布较合理。     

铸铣件的浇注系统和冒口 第六讲 防止铸件产生缩孔、缩松的方法

为了防止铸件中产生缩孔,我们应该根据不同的合金凝固特点和铸件结构,制定合理的铸造工艺来有效地控制凝固过程,以便建立良好的补缩条件,尽可能使缩松转化为集中缩孔,并使它移向铸件最后凝固的地方。这样就可以在铸件最后凝固的地方设置冒口,使缩孔移入冒口内,从而获得致密的铸件。     

铝合金汽车轮毂铸件凝固过程缺陷CAE分析

用对比定量的方法研究了浇注温度、模具预热温度对模具温度场的影响,探讨了冷却方式、浇注速度及模具结构对铸件缺陷的影响.运用某铸造模拟软件对其模具及铸件进行了压铸过程温度场分析和轮毂低压铸造充型及凝固过程做了模拟分析,介绍了铸件缺陷-缩松,缩孔的成因,利用CAE技术分析了铝合金汽车轮毂在凝固过程中浇注速度、冷却方式对缩松,缩孔的影响。     

微车制动产品铝合金重力铸造缺陷分析及改进

采用铸造专用软件Pro Cast2004对现有铝合金铸件铸造工艺进行充型过程、凝固过程和疏松、缩孔位置等方面的分析,同时结合实际工艺试验的结果分析,模拟预测出可能产生的缺陷(气孔、缩孔和缩松),从而判断浇注系统的浇冒口设置、浇铸工艺和操作程序等的合理性,并通过工艺验证进行验证,从而提供现有铸造模具和工艺对产品品质影响的关系,并制定了改进措施。     

ZL104铝合金刀盘体的铸造工艺优化

公司生产的ZL104铝合金刀盘体铸件厚壁处常出现缩松缩孔缺陷。使用芸峰CAE软件对此盘体原有的铸造工艺进行凝固过程模拟仿真,预测缩松缩孔缺陷位置与实际生产相吻合。优化工艺后,再次用CAE软件进行模拟仿真,得到合理的方案后,在实际生产中应用,毛坯加工后该区域的缩松缩孔完全消除,获得了合格零件。     

大型球磨机端盖铸造工艺模拟及优化

利用三维绘图软件生成球磨机端盖铸件实体模型,运用华铸软件对球磨机端盖铸造工艺进行温度场的数值模拟,预测缩孔、缩松等缺陷产生的部位,并分析形成原因。根据模拟结果对冒口、冷铁尺寸进行改进,优化工艺。改进的工艺实现了顺序凝固,消除了缩孔、缩松缺陷,保证了铸件质量。     

某铝合金铸件石膏型低压铸造工艺的模拟及优化

采用石膏型低压铸造过程工艺生产某铝合金铸件,经X光检测发现,其特定部位存在缩孔和缩松等缺陷。运用FLOW-3D软件对铸造工艺进行分析,并对其充填及凝固过程进行了模拟。依据模拟结果,对原铸造工艺进行了优化设计,并再次进行充填和凝固模拟,结合模拟结果制定出合适的工艺。生产实践表明,优化工艺所设置的冒口、冷铁规格和位置是合理的,有效解决了生产过程中出现的问题。     

铸铣件的浇注系统和冒口 第五讲 灰铸铁与球铁缩孔、缩松的形成

第五讲灰铸铁与球铁缩孔、缩松的形成缩孔和缩松是铸件上常见的一种缺陷。要避免这种缺陷的产生,铸造工人就需要知道铸铁的收缩规律,缩孔和缩松的形成原因,体积的大小、形状及分布的规律,以及掌握防止这些缺陷的工艺措施。一、铸铁的收缩一般的物体具有热胀冷缩的规律。高温的铁水浇入砂型后,从冷却凝固直至降到常温,在这个过程中,体积会出现减小的现象,我们称为收缩。如果我们对收缩过程不采取必要的工艺措施,铸件往往会出现缩孔、缩松、裂     

铁路客车转向架用轴箱盖铸造凝固模拟及工艺优化

铸造凝固模拟软件作为一种有效的铸造工艺设计和优化工具．在全球铸造行业中得到了广泛的应用。本文针对铁路客车转向架用轴箱盖存在的缩孔和缩松等缺陷,结合现场铸造工艺情况,利用MAGMA软件对其凝固过程进行了数值模拟,并根据模拟结果对轴箱盖的两种铸造工艺方案进行比较,选出一种最优的方案,使铸件的冒口补缩和凝固过程更加合理。     

A new shell casting process based on expendable pattern with vacuum and low-pressure casting for aluminum and magnesium alloys

A new shell casting process, with the adoption of the foam pattern of lost foam casting (LFC) as prototype and the combination of the thin shell fabrication technology of investment casting and vacuum and low-pressure casting process, was proposed for manufacturing complicated and thin-walled aluminum and magnesium alloy precision castings. Loose-sand uniting vacuum was used in the new process to further reinforce the thin shell, and the new process proves to be a process with simple process, low cost, and high thin shell strength. Because the molten metal filling and solidification are completed under air pressure and vacuum level, the filling capability and feeding capacity of the molten metal are greatly improved, and the castings become denser. This paper mainly investigated the fabrication technology of thin shell based on foam pattern prototype, the removing foam and roasting shell process and vacuum and low-pressure casting process. The few-layer compound thin shell of silica sol–sodium silicate was adopted for the new process. Removing foam pattern was carried out at 250°C for 30 min, and the shell was roasted at 800°C for 1 h. Combined with the vacuum and low-pressure casting process, this new shell casting process has successfully produced thin wall and complex aluminum and magnesium alloy parts with high quality. In addition, comparisons in terms of filling ability, microstructure, mechanical properties, porosity, and surface roughness among this new shell casting, gravity casting, and LFC were also made to show the characterization of this new shell casting process.     

An investigation on enhancing ceramic shell properties using naturally available additives

The ceramic shell properties are very crucial in investment casting (IC) process. Colloidal silica based ceramic shells usually lack sufficient shell properties which causes shell cracking. Sometimes minor repairs can make up the shells. However, every time shell repairing may not be feasible which causes loss to the manufacturer. In the present work, an investigation has been made to improve the properties of colloidal silica based IC ceramic shell by addition of naturally available products such as saw dust and coconut fibres into the ceramic slurries. The important shell properties tested were shell thickness, green and fired strengths, porosity and permeability. The properties of saw dust and coconut fibre modified shells were compared with that of conventional ceramic shell using statistical analysis and it was found that the new shells were better than the conventional shell in terms of shell properties. Further, it was found that the aluminium alloy casting obtained from new shells showed comparatively increase in tensile strength and reduced porosity with that obtained from the conventional ceramic shell. The adopted method proved effective in reducing both production lead time and cost of manufacturing the qualitative IC ceramic shells.     

复合铸造技术在特种产品上的应用

介绍了将复合铸造技术运用到航空炸弹中的复杂工件,特别是大型薄壁铝合金舱体的优势。分析了石膏型熔模铸造结合真空增压技术的特点,同时,采用该技术研制大型复杂薄壁铝合金铸件,通过合理设计铸件浇注系统,选择铸型工艺,优化浇注工艺参数和严格控制固溶处理温度与校形时机,提高了铝合金的充型能力,改善了铸件的致密度和针孔度,解决了大型薄壁铸件充型及内部质量难以控制的难题。     

数值模拟优化DISA薄壁铸铁管铸造工艺参数

采用MAGMASOFT软件, 对迪砂线(DISA)生产条件下、 不同设计参数玛钢管件的充型和凝固进行了数值模拟计算, 并通过热判据对疏松缺陷进行了判定. 基于数值模拟结果, 讨论了浇道设计比率和冒口位置对疏松的影响规律. 结果表明, 直浇道截面尺寸对充型顺序影响显著, 可通过锥形直浇道设计和多个截面的内浇道合理匹配来解决流量不平衡问题. 同时, 在热节处设置冒口用于铸件的补缩. 通过优化设计浇注系统和冒口系统最终消除了铸件的缩松缺陷.     

Study on direct fabrication of ceramic shell mold with slurry-based ceramic laser fusion and ceramic laser sintering

Through studying the porosity of the ceramic parts fabricated with slurry-based rapid prototyping process of ceramic laser fusion and ceramic laser sintering, the feasibility of directly fabricating ceramic shell mold was investigated in this paper. Although the total porosity of the fusion part was low, microcracks led to low strength, which was hardly enhanced by post-treatment of infiltration. On the other hand, by adjusting the slurry formulation and varying the laser scanning energy, the open porosity of the sintered part was over 90?vol.% of the total porosity. High open porosity resulted in good permeability, which is one of the important characteristics of the ceramic shell mold for investment casting. To verify the feasibility of producing casting part with ceramic shell molds fabricated by the processes of ceramic laser fusion and ceramic laser sintering, the casting process was conducted to obtain the casting parts.     

Analytical modeling of ductile-regime machining of tungsten carbide by endmilling

The aim of the present research was to compare the efficacy of two powder based 3D printing technologies for rapid casting of light alloys. The technologies of ZCast process and investment casting were employed to cast aluminium A356 alloy and zinc ZA-12 alloy. The split pattern shells were printed in ZCast501 powder and used directly as mould with outside sand support in case of ZCast process. Two commercially available powders starch-based ZP14 and plaster-based ZP100 were infiltrated with two infiltrants acrylate and wax resulting in four different material systems for making investment casting patterns. A standard method was premeditated by identifying and designing the benchmark component. The proposed concept was presented in physical form by fabricating prototypes to appraise the impact of technology used on dimensional accuracy. The dimensional accuracy was acceded by assigning tolerance grades as per UNI EN 20286-1 ISO. In addition, the working suitability of castings was analysed by comparing important mechanical properties, and further, the results were supported by radiography and microstructure analysis. The feasibility of decreasing shell wall thickness for ZCast process was also checked so as to make the process more economical and fast.     

自动变速箱油泵盖低压铸造工艺开发应用

介绍自动变速箱油泵盖低压铸造工艺开发应用经验,针对生产中发生的缩孔、缩松、气孔等缺陷制定合理的控制措施。     

镁合金真空低压消失模铸造新技术

介绍了一种新的铸造技术--真空低压消失模铸造的工作原理.建立了其在充型过程中的物理模型与数学模型,分析了其铸造工艺的特点及影响因素,以及在铸造高精度、复杂镁合金铸件方面的优势.作为压力铸造、低压铸造的补充,真空低压消失模铸造新技术在铸造高质量和高精度的镁合金铸件中具有广泛的应用前景,另外还可用于铸造高精度、复杂的铝合金铸件.展示了用该新技术铸造成形的复杂的电机壳体、排气管等镁合金铸件.