AM60B镁合金压铸模浇注系统的模拟与优化

设计出2种类型的镁合金压铸浇口及浇注系统,运用模拟软件对2种浇注系统进行模拟,分析液态金属充型及凝固过程中流场和温度场的分布。根据凝固规律有效预测铸件中可能存在的缩孔及气孔缺陷的分布,优化浇注系统结构。结果表明:在浇注温度690℃、模具初始温度200℃、冲头压射速度3m/s条件下,压铸件质量较好。     

铝合金支架压铸数值模拟及压铸工艺研究

利用ProCAST铸造模拟软件,对铝合金压铸件支架充型、凝固过程进行了数值模拟,得到了速度场、温度场的分布和变化规律。结果表明,浇注温度对压铸铝合金的模拟结果影响最大,其次为模具预热温度、充型速度。本试验条件下得到的优化工艺参数:浇注温度为600℃,模具预热温度为200℃,充型速度为2.5m/s。按照优化后的压铸工艺参数进行生产,得到了合格的铸件。     

铝合金压铸工艺数值模拟分析

采用压铸工艺成形铝合金薄壁长轴类零件。首先根据压铸模具浇注系统的设计原则,对铝合金件压铸模的浇注系统进行了设计计算;其次运用procast软件对铝合金压铸成形工艺进行数值模拟,根据压铸过程中的温度场云图,进行了压铸模具的热平衡分析和压铸件的充型凝固分析;最后针对模拟的结果进行了压铸模具的设计。     

镁合金缸盖罩T型浇注系统优化设计与数值模拟

基于现有镁合金汽车发动机缸盖罩T型浇注系统结构分析,对其横浇道厚度和排溢系统结构尺寸进行优化。结合压铸数值模拟软件JScast对其进行压铸数值模拟试验,确定压铸充填与凝固过程温度场分布情况及其金属液的流动情况,对其进行缩松、缩孔和流痕等缺陷预测,并采取相应的措施以提高压铸充填效果和压铸件的质量。结果表明,优化后的铸件总体积较优化前减少2.5%,且充填效果良好,验证了压铸数值模拟技术的可靠性。     

镁合金汽车座椅靠背骨架压铸浇注系统设计与优化

设计了两种镁合金汽车座椅靠背骨架压铸浇注系统,运用Pro CAST数值模拟软件对两种浇注系统实现的充型过程进行模拟。通过观察流场、表面缺陷的分布情况并进行分析,预测充型过程中的氧化夹渣等缺陷。在分析模拟结果的基础上提出了浇注系统的优化方案,提高了铸件的质量。     

基于ProCAST对汽车附件支架压铸过程的数值模拟分析

使用Solidworks软件对活塞支架及整个浇注、溢流系统进行了三维实体建模。采用数值模拟软件ProCAST对其初始的压铸工艺参数进行了数值模拟,对充型及凝固过程进行了分析,发现铸件缩孔缺陷比较严重。然后对其铸件结构进行优化,最终获得满意的结果。     

滤清器壳体压铸工艺设计及数值模拟

根据滤清器壳体的结构特点,设计了压铸工艺方案,采用Flow-3D软件对压铸工艺方案进行数值模拟,通过分析卷气的分布情况预测产生缺陷的位置。初始方案模拟结果表明,型腔中间及两端存在较多卷气,容易产生气孔、缩松等缺陷。通过温度场分布判断压铸件凝固方式为逐层凝固,说明充型过程合理。优化方案调整了浇注系统的形状和位置,增强了溢流槽收集气体的能力。结果表明,铸件内卷气明显下降,缺陷消除,满足生产要求。     

汽车发动机镁合金缸盖罩充型及凝固模拟

运用JSCAST软件,模拟AZ91D镁合金汽车发动机缸盖罩液态压铸充填过程及凝固过程,通过分析充型过程以及凝固过程的模拟结果进行浇注系统的优化设计,按照优化后的浇注系统再次进行充型与凝固模拟验证,对其产生的缺陷进行分析,进一步优化工艺参数。经分析验证证明：所设计的浇道及溢流槽、排气槽合理,整个充填过程平稳。     

基于数值模拟的锁芯压铸模设计

运用数值模拟的方法,对设计的锁芯压铸模不同的浇注系统和溢流系统进行模拟,分别观察液态金属充型及凝固过程中流场和温度场的分布.根据凝固规律有效预测锁芯可能存在的缩孔及气孔缺陷的分布及尺寸,改进浇注系统和溢流系统,并对模具的其它部分进行改进.     

轴承支架半固态压铸过程数值模拟

采用数值模拟方法分析了半固态铝合金的表观粘度及浇注温度对轴承支架铸件压铸充型和凝固过程的影响。结果表明,半固态铝合金的充型速度随其表观粘度的增加而显著下降,而浇注温度对充型速度的影响与液态压铸时的一致。铸件同一部位的凝固温度随半固态铝合金浆料充型时的表观粘度增加而提高。凝固后铸件内未出现铸造缺陷。     

CAE模拟分析在前盖压铸模设计中的应用

应用Anycasting软件对铸件的填充过程、凝固过程和模具温度场进行模拟分析,利用模拟结果优化模具结构,尽量避免模具设计对铸件质量产生的不利影响,降低铸件缺陷产生的概率,缩短产品开发周期。     

压铸成形减震器支撑件浇注系统的改进设计分析

采用数值模拟软件ProCAST,对减震器支撑件压铸模浇注系统改进前、后的成形过程进行分析,综合分析零件充型过程、温度场、凝固场以及缺陷分布云图,结合实物试验准确预测铸件的缺陷位置和形式。数值模拟结果具有较高的可信度。改进浇注系统后成形的零件缺陷倾向明显减小,数值模拟技术有效降低试模风险和成本,缩短模具改进设计周期和提高产品的质量。     

铝合金压铸件凝固过程中的瞬态温度场分析

建立了铝合金压铸件的有限元模型,确定了温度场模拟的初始条件和边界条件;结合材料的热物性,利用AN-SYS软件对A380.0铝合金压铸件凝固过程中的温度场进行了模拟,得到了铸件各点温度随时间变化的规律,模拟结果反映了铸造系统温度的变化过程。结果表明：利用ANSYS模拟温度场运算速度快、结果比较准确,为热应力分析提供了温度场条件,并给压铸优化设计提供了依据。     

箱体低压铸造过程的数值模拟

以计算流体力学和计算传热传质学作为理论基础,利用大型模拟软件ANSYS对箱体的低压铸造过程进行了数值模拟,分析了铝合金在低压铸造充型过程中的流场以及凝固过程中的温度、固相分数的分布情况,预测铸件可能出现的缺陷,为优化铸造工艺和模具设计提供参考。     

Numerical simulation and optimization of Al alloy cylinder body by low pressure die casting

Shrinkage defects can be formed easily at critical location during low pressure die casting （LPDC） of aluminum alloy cylinder body. It has harmful effect on the products. Mold filling and solidification process of a cylinder body was simulated by using of Z-CAST software. The casting method was improved based on the simulation results. In order to create effective feeding passage, the structure of casting was modified by changing the location of strengthening ribs at the bottom, without causing any adverse effect on the part＇s performance. Inserting copper billet at suitable location of the die is a valid way to create suitable solidification sequence that is beneficial to the feeding. Using these methods, the shrinkage defect was completely eliminated at the critical location.     

数值模拟技术在汽车齿轮室模具温度场分析中的应用

以汽车齿轮室压铸件为例,对铸件凝固过程进行分析,使用模拟软件Flow-3D得到了压铸镁、铝合金模具温度场的分布特征,研究了镁、铝合金压铸件及压铸模具温度场随浇注温度、模具预热温度变化的情况。数值模拟结果可为汽车齿轮室模具优化设计提供参考。     

基于数值模拟的发动机缸体压铸模浇注系统优化设计

针对镁合金发动机缸体设计了2种不同类型的浇注系统,运用铸造模拟软件ProCAST对2种浇注系统下铸件的充型和凝固过程进行模拟,预测了充型时间、凝固时间和铸件中可能存在的缩孔、疏松及气孔缺陷的分布与尺寸,提出了优化的浇注系统设计。结果表明:在浇注温度670℃、模具初始温度220℃、压射速度8.5m/s的条件下,扇形浇注系统设计优于梳形浇注系统设计。     

Influence of die casting process parameters on castability and properties of thin walled aluminium housings

Abstract

The objective of this study is to clarify effects of high pressure die casting process parameters for castability and mechanical properties. So the optimal die casting conditions for producing for thin walled Al component was conducted computational solidification simulation and actual die casting with three different venting systems, four straight, checker and full checker vent. Furthermore, the die casting process parameters, such as die controller temperature, high injection speed and die open time, were experimentally evaluated. The results of computational solidification simulation were found that the control of process parameters could lead to soundness of surface and no defect and improvement of mechanical properties. As increasing the high injection speed from 2˙0 to 4˙0 m s^?1 and die temperature, the castability was increased. The full checker venting system had best castability with good surface quality among the three cast specimens.     

Interfacial heat transfer behavior at metal/die in finger-plated casting during high pressure die casting process

Heat transfer at the metal-die interface has a great influence on the solidification process and casting structure. As thin-wall components are extensively produced by high pressure die casting process(HPDC), the B390 alloy finger-plate casting was cast against an H13 steel die on a cold-chamber HPDC machine. The interfacial heat transfer behavior at different positions of the die was carefully studied using an inverse approach based on the temperature measurements inside the die. Furthermore, the filling process and the solidification rate in different finger-plates were also given to explain the distribution of interfacial heat flux(q) and interfacial heat transfer coefficient(h). Measurement results at the side of sprue indicates that qmax and hmax could reach 9.2 MW·m~(-2) and 64.3 kW ·m~(-2)·K~(-1), respectively. The simulation of melt flow in the die reveals that the thinnest(T_1) finger plate could accelerate the melt flow from 50 m·s~(-1) to 110 m·s~(-1). Due to this high velocity, the interfacial heat flux at the end of T_1 could firstly reach a highest value 7.92 MW·m~(-2) among the ends of T_n(n=2,3,4,5). In addition, the q_(max) and h_(max) values of T_2, T_4 and T_5 finger-plates increase with the increasing thickness of the finger plate. Finally, at the rapid decreasing stage of interfacial heat transfer coefficient(h), the decreasing rate of h has an exponential relationship with the increasing rate of solid fraction(f).     

Comparison of mechanical properties of die cast aluminium alloys: cold v. hot chamber die casting and high v. low speed filling die casting

Abstract

In this paper, the mechanical properties of die cast aluminium alloys made by various die casting technologies were examined. To create high quality aluminium alloy die castings, two die casting processing technologies were employed. These were (a) ultra slow speed filling cold chamber die casting and (b) high speed hot chamber die casting. Significant improvements of the fatigue and mechanical properties were obtained for both die casting systems compared to the normal high speed cold chamber die casting technique. By comparing ultra slow die casting with hot chamber die casting, it was found that the fatigue and mechanical strengths from hot chamber die casting were higher than those for ultra slow filling die casting. The differences in material strength were attributed directly to the material properties, e.g. microstructural morphology and internal defects. Spherical fine dendritic cells in the hot chamber die casting sample gave rise to high fatigue crack growth resistance; the low crack growth resistance for cold chamber die cast aluminium is mostly due to the growth of aluminium rich α phase and the presence of eutectic silicon fibres. The fatigue strength was also related to the number of internal defects, e.g. the lower the defect rate on the fracture surface, the higher the fatigue resistance and mechanical strength. The characteristics of the principal internal defect were different depending on the die casting technology: this showed fine porosity for hot chamber die casting but solidification shrinkage and the scattered chill structure for slow and high speed cold chamber die castings. The reasons for the change of material strength were therefore influenced by the die casting process.