3D打印砂型在铸造中的应用

介绍了3D打印机的工作原理及在砂型铸造中的应用,列举了3D打印技术在工程机械铸件新产品开发、汽车铸件新产品开发及航空复杂铸件上的应用,得出以下结论:(1)采用3D打印铸件砂型,浇注的铸件精度高、披缝少、易清理,新产品开发速度快,适用于新产品开发和复杂件单件小批量的生产;(2)3D打印工艺的设计更改只需要更改三维模型,因而可以快速切换、升级;(3)高端砂型依赖进口设备和原材料,3D打印成本相对较高,是传统铸造的补充,对于普通铸造无法生产的铸件砂型,可以使用3D打印来完成。     

基于砂型3D打印泵体的铸造工艺研究

以泵体为研究对象,就数值模拟和砂型3D打印技术在砂型铸造中的应用进行了研究,利用Anycasting软件比较了泵体铸件侧注式、顶注式和底注式浇注方案,并确定侧注式浇注系统为最佳选择。采用3D打印技术对泵体砂型进行了制作,采用砂型铸造工艺制备出了合格铸件。结果表明,数值模拟结合砂型3D打印技术在铸造中的应用,可有效缩短零件开发周期,降低生产成本,大大提高了生产效率。     

3D打印技术用于砂型铸造工艺品的实践

采用3D打印的PLA工艺品模型,预埋于粘土砂型中,在模型底部设置熔融PLA流出孔。在高温作用下,使模型融化,得到完整型腔。合上上型,放置浇口杯,浇注金属液得到完整铸件。冷却完毕,经清理后,在铸件表面涂覆腻子膏并上色,得到理想创意工艺品,完成了试验。     

铸造砂型3D打印技术应用及选型分析

研究了当前铸造砂型3D打印机的应用原理、工艺流程及主要性能,并对选型参考、应用等方面进行分析。结果表明,砂型3D打印技术相比传统树脂砂铸造技术有其先进性及优势,企业用户在选择砂型3D打印设备时,需根据自身企业产品的特点综合考虑,砂型3D打印在铸造上的应用工艺已相对成熟。     

砂型3D打印技术在汽车发动机缸体铸造中的应用

近年来,3D打印技术取得了较快的发展,并在各行各业中得到应用。在铸造行业中,3D打印技术的应用越来越广泛。本文结合3D砂型打印技术原理和技术特点,具体介绍了砂型3D打印技术在汽车发动机缸体铸造中的应用。     

3D打印砂型性能各向异性研究

介绍了3D打印砂型性能的各向异性,研究了经喷墨3D打印成型的砂型X、Y、Z 3个方向性能的差异大小和影响因素:首先,将用于测试的砂型试块用喷墨3D打印机打印成型,测试试块拉伸性能,确定试块X、Y、Z 3个方向性能差异大小;其次,更改喷墨打印参数,验证各项参数对X、Y、Z 3个方向性能影响的大小;最后,确定喷墨打印砂型X、Y、Z 3个方向性能差异的具体数值并得出降低X、Y、Z 3个方向性能差异的方法。得出结论:通过调整各向打印参数寻找合适匹配关系,可有效降低砂型各向性能之间的差异,提高砂型的综合性能,以满足实际生产的需求。     

3D打印在铸造技术中应用

介绍了3D打印的基本概念、技术原理及发展历程,对其结合传统铸造技术进行优势互补,所形成的快速铸造工艺进行了总结,并对快速铸造在国内外的发展现状进行了阐述。从快速铸造中的应用分类、工艺流程图和实际案例三个方面对3D打印技术在铸造中的应用进行了总结和分析,阐明了多种快速铸造技术原理、研制经历和若干知名公司的技术特点。最后对3D打印技术的应用发展进行了展望,3D打印技术的发展必将给铸造业带来一场新的技术革命。     

基于砂型(芯)3D打印的阀门生产工艺实践

以阀门整体砂型(芯)为例,分别从打印设备、工艺制定、质量评定等环节阐述了 3D打印在企业生产应用现状,介绍了砂型3D打印在阀门砂型铸造中的应用.结果表明,3D砂型(芯)表面光洁,模型存在阶梯效应,砂型强度满足生产需求.运用3DP技术结合铸造工艺,生产了材质为Z3CN20-09M,6J300核级截止阀,铸件尺寸精度和表面...     

砂型3D打印原材料标准解读北大核心

对中国机械工程学会发布的《铸造用3D打印呋喃树脂》《铸造用3D打印固化剂》《铸造用3D打印硅砂》等三项标准进行了系统解读，详细介绍了标准中涉及的电导率、堆积密度、颗粒度等技术指标设立的目的、检测方法选择、等级设置原则等，对铸造用3D打印原材料的应用机理做出探讨，并对相关标准的国内外概况及重要意义进行了介绍，最后对3DP标准未来的发展趋势进行了展望。     

树脂渗透对砂型3D打印成型精度影响机理研究

研究了树脂渗透对砂型3D打印成型精度的影响,提出对应的理论模型,并进行实验验证.结果 表明:树脂渗透通过树脂加入量、水力半径和铺砂厚度影响砂型打印成型精度,与成型尺寸无关.随着树脂加入量的增大,树脂渗透压力增大,尺寸误差增大;固化剂含量与型砂颗粒直径的增大均会导致型砂水力直径增大,进而导致尺寸误差变大;铺砂层厚的增大导...     

Effect of gel time of 3D sand printing binder system on quality of sand mold/core

Two important factors affecting the performance of sand mold/core generated by 3D printing (3DP) are strength and dimensional accuracy,which are not only closely related to the reactivity of furan resin and the phase transition of silica sand,but also the curing agent system of furan resin.This paper studies the influence of gel time on the strength and dimensional accuracy of a 3DP sand mold/core,taking the furan resin system as an example and using a sand specimen generated by a 3DP inkjet molding machine.The experiment demonstrates that the gel time of 3 to 6 min for the sand mixture suits 3DP core-making most under the experimental condition.However,it should be noted that under the same resin condition,the strength of a no-bake sand mold/core is higher than that of a 3DP sand mold/core.The dimensional accuracy of the sand mold/core does not change significantly when the gel time is less than 15 min.Improving the activity of binder and developing ultra-strong acid with low corrosion shall be an effective way to improve the quality of the mold/core by 3D printing.     

选择性激光烧结工艺参数对影响铸造砂型精度的优化设计

阐述了选择性激光烧结(SLS)的成型原理,并将此成型方式运用于直接砂型制作。通过用自主研制的快速成型机进行烧结试验,采用正交试验和方差分析,对影响铸造砂型精度的工艺参数进行了优化设计,得到激光功率、扫描速度、扫描间距及铺粉厚度工艺参数的最佳组合,可为基于选择性激光烧结铸造砂型的制造提供指导和参考。     

Sand-bed defect recognition for 3D sand printing based on deep residual network

The 3D sand printing (3DSP), by binder jetting technology for rapid casting, has a pivotal role in promoting the development of the traditional casting industry as a result of producing high-quality and economical sand molds. This work presents an approach for monitoring and analyzing powder sand-bed images to serve as a realtime control system in a 3DSP machine. A deep residual network (ResNet) is used to classify the defects occurring during the powder spreading stage of the process. Firstly, a pre-trained network was applied as the initial parameter; then it was fine-tuned on the labelled defective sample dataset to accomplish the task, which defines the sand-bed defects induced in the 3DSP processing. Furthermore, the recognition and positioning of sand-bed defects were readily achieved by dividing the sand-bed images into blocks. Experiments show that the fine-tuned network has a 98.7% classification accuracy on the validation dataset of sand-bed defects and 95.4% recognition accuracy for the sand-bed images.     

Cooling control for castings by adopting skeletal sand mold design

The cooling control of the melt during the casting process is of great significance. A comprehensive closed-loop cooling control of castings by adopting a skeletal sand mold design was proposed. The skeletal sand mold consisting of an adaptive shell, functional cavities and a support was designed and created based on the finite difference meshes of a casting. It was applied to a round wall test casting. Two kinds of skeletal sand molds, one with lattice support and the other with enforcing ribs for this casting were designed and printed out by the 3 D printing(3 DP) method. Aluminum alloy A356 was cast by using these two sand molds. The first mold was cooled by natural convection, the other one by water spray cooling. Two sound castings were obtained. The sand mold temperature, cooling curves, microstructures, mechanical properties, residual stress and deformation were measured, compared and discussed. Water spray cooling hastened the cooling rate by 62%, increased the content of Mg and Cu in the α-Al matrix, improved the mechanical properties, and altered the surface residual stress state.     

基于3D打印的玩具枪弹夹模具水路设计

以玩具枪弹夹为研究对象,借助UG软件进行产品建模,利用Moldflow模流仿真对塑件进行水路设计。通过对传统水路和跟形环绕设计的随形水路两种方案的冷却效果对比,结合实际水路加工工艺,确定了最优水路设计方案,为多孔深腔类模具水路设计提供参考示例。经过实际生产验证,与传统水路相比较,采用跟形环绕随形水路产品的生产周期由55s缩短至35s,效率提升了36个百分点以上。     

铝-硅合金砂型铸件改为压铸生产的工艺改进

通过一个铝-硅合金端盖压铸件设计实例,探讨了铝-硅合金砂型铸件改为压铸生产时,要在合金化学成分、熔炼工艺和铸件的工艺性能等方面,根据压铸工艺的特点对铸件整个生产工艺进行改进,以满足压铸生产的特殊要求。压铸铝-硅合金中ω（Fe）可以达到1．0％。ω（Fe）〈0．150%时,ω（Mn）要达到0．5％-0．8％,以防止粘模。对于不太重要的铝合金压铸件可以省略熔炼过程中的变质处理过程,通过合理设置加强筋、减少壁厚、减小拔模斜度等措施,改善压铸件的结构工艺性。     

基于3D打印技术的铸造起重机车架轻量化研究

铸造起重机,是依靠沿厂房轨道方向的纵向移动、小车的横向移动和吊钩的升降运动来进行搬运工作的机器。其中小车架作为起重机的主要部件之一,约占起重机总重量的16%,起着主要的承载作用,因此设计出合理的小车架结构对起重机整体的安全性、经济性有很重要的意义。以10 t铸造起重机车架为研究对象,设计以3D打印技术为主要加工方法的新型车架。首先,以车架钢板为坐标平面建立坐标系,并根据车架上减速器座,电机座,定滑轮等放置的位置为坐标点输入坐标系,确定切割的位置、尺寸,结合ANSYS有限元分析软件,通过分析车架整体结构的应力及变形情况,对车架进行局部优化。结果表明:以3D打印技术进行切割设计的起重机车架与原起重机车架强度相仿,重量减少169 kg,减重部分占改进前车架重量的17.4%。     

The role and impact of 3D printing technologies in casting

3D printing is such a magical technology that it extends into almost every sector relating to manufacturing, not to mention casting production. In this paper, the past, present and future of 3D printing in the foundry sector are profoundly reviewed. 3D printing has the potential to supplement or partially replace the casting method. Today, some castings can be directly printed by metal powders, for example, titanium alloys, nickel alloys and steel parts. Meanwhile, 3D printing has found an unique position in other casting aspects as well, such as printing the wax pattern, ceramic shell, sand core, sand mould, etc. Most importantly, 3D printing is not just a manufacturing method, it will also revolutionize the design of products, assemblies and parts, such as castings,patterns, cores, moulds and shells in casting production. The solid structure of castings and moulds will be redesigned in future into truss or spatially open and skeleton structures. This kind of revolution is just sprouting, but it will bring unimaginable impact on manufacturing including casting production. Nobody doubts the potential of 3D printing technologies in manufacturing, but they do have limitations and drawbacks.     

基于3D打印与三维图像处理的服装信息提取方法研究

在形状基不定情况下,对三维服装信息提取过程存在特征关联较弱,分割区域扩大等问题.为此,提出一种基于3D打印与三维图像处理的服装信息提取方法.首先对采集的服装三维图像进行纹理特征分割,图像序列自适应块匹配方法进行信息增强处理,然后采用桌面型3D打印技术进行服装设计中的图像三维重构,进行服装三维图像表面渲染,实现服装信息提取.最后通过仿真实验进行性能测试,结果表明:采用该方法进行服装信息提取,能准确反映服装的纹理信息和三维渲染信息,服装设计的色彩均衡性较好,有效指导服装设计优化.     

基于3D打印技术的模具制造

本文以某限位块模具型芯为例,利用生产浪费最小、能量消耗最低、污染排放最小的3D打印技术理念生产制造,打破了传统的模具设计与制造方法,从而可以实现绿色模具和快速模具制造。