剥模树脂砂造型若干技术问题探讨

正我厂是传统木模树脂砂铸造厂,自2011年引入剥模树脂砂造型工艺,以应对当前的市场需求。与传统木模树脂砂造型相比,剥模树脂砂造型具有节能环保、成本低、设备需求低、可循环利用等特点。剥模树脂砂造型工艺,是采取特殊的工艺手段用泡沫制作模样、芯盒,然后用树脂砂造型的方式。1.剥模树脂砂造型的适用范围(1)小批量产品订单较少、形不成批量的产品,制作木模成本高。(2)单件或大件某些吨位较重、客户需求量少的产品,制作木模成本高。     

呋喃树脂砂木模设计

树脂砂铸件表面平整、棱角清晰、尺寸精度高等优点首先取决于模样的质量。树脂砂用模样无论在结构上,还是在工艺参数上都与粘土砂用模样有许多不同之处。因此在推行树脂砂新工艺时,优化木模结构、合理确定参数是充分发挥树脂砂优势获得优质铸件的前提。     

聚氨脂树脂砂性能研究

研究了HG、CP和NP三种聚氨脂树脂砂的透气性、发气量和在不同加热条件下的残留强度.结果表明:HG系列树脂砂透气性最高,CP系列树脂砂发气性总体上要优于其它两种树脂砂,发气量相对较低.树脂砂的高温残留强度随加热时间的增加而降低,加热温度越低,残留强度降低的幅度也越小;随着加热温度升高,树脂砂的残留强度显著下降,在500℃加热10min时,所有配比树脂砂的残留强度趋于零.CP2配比的树脂砂在透气性、发气性、溃散性和低温强度等方面有较好匹配,能更好地满足薄壁复杂铝合金件铸造成形需求.     

树脂砂生产大型铸铁件的工艺分析与质量控制

依据对树脂砂生产大型铸铁件的特性分析，阐述了用树脂砂生产大型铸铁件的铸造工艺要点与关键工序的过程质量控制。通过介绍几种典型大型铸铁件用树脂砂生产的实例，具体说明了提高树脂砂生产大型铸铁件质量的生产工艺方法。     

树脂砂砂型用棕刚玉粉涂料

树脂砂工艺生产铸钢件,具有铸件表面质量好、尺寸精度高、生产周期短及自动化程度高等优点。但铸件也容易产生粘砂、气孔等缺陷。因此在树脂砂砂型上使用涂料是十分重要的,好的铸型涂料可以有效地防止这些铸造缺陷的产生。 1.树脂砂砂型对涂料的要求 树脂砂有其自身的特点,这些特点主要表现在: (1) 树脂砂与粘土砂、水玻璃砂相比较,由于采用了有机粘结剂,当高温钢液浇入砂型后,树脂砂型     

树脂砂工艺参数的探讨

简述了树脂砂工艺的主要特点, 介绍了树脂砂的主要工艺参数     

自硬树脂砂模样的工艺特点

随着对铸件质量要求的不断提高和出口产品的日益增加,自硬树脂砂在铸造业的应用越来越广泛,这是当前铸造技术改造的新趋势.采用自硬树脂砂生产铸件除了掌握其工艺性能外,还必须考虑自硬树脂砂的特点,解决好模样、芯盒的工艺.模样的工艺对铸件的质量和尺寸精度起着重要的作用.下面介绍我们的初步实践经验.一、模样的材料实践证明,木模、金属模、塑料模均适用自硬树脂砂.由于自硬呋喃树脂砂在硬化过程中的反应是放热反应,其副产物是水,而塑料模、金属模不吸水,且金属模导热性好,尤其     

UPF常温自硬树脂砂制芯工艺研究

自常温自硬树脂砂问世以来,国内外铸造界进行了大量的实验、研究工作,呋喃型、酚醛型等常温自硬树脂砂相继得以推广应用.目前,可使用时间达2小时的常温自硬树脂砂还很少公开报道.为了满足中小型铸造厂使用自硬树脂砂造型制芯要求,我们开展了UPF常温自硬树脂砂实验研究工作.     

机械信息

江苏省召开树脂砂研讨会江苏省铸造学会于1990年11月28日至30日在南通市召开树脂砂研讨会。省铸造学会四届全体理事与省内有关企业代表共108人参加了会议。会上东南大学刘承尧副教授作了有关国内外树脂砂述评的报告;南通机床厂、苏州液压件厂、无锡机床厂等6个单位介绍了树脂砂应用情况;观看了美国福特汽车公司、约翰·迪尔拖拉机公司以及中国长春汽车厂等国内、外厂家应用树脂砂录相。还参观了南通燕东铸造公司与南通机床铸造厂冷硬法造型、制芯现场。与会代表一致认为,这是一次理论联系     

树脂砂造型脱模剂的试制及其应用

铸造业使用树脂砂造型其优点是:提高铸件尺寸精度及内在质量,减少机械加工余量,砂型不需烘干,节约能源,从而缩短生产周期,能大大减轻工人的劳动强度,改善劳动环境。易于实现大批生产和流水作业。但在使用树脂砂生产中,脱模难是我们遇到的一个突出的问题。即在树脂砂充型后,随着     

覆膜砂用原砂的预处理

这里概述了覆膜砂用原砂的四种预处理：原砂纯洁度及净化处理，调整砂子粒度和粒度组成及粒形选择，改善原砂表面状态及人工复合处理。     

XC-HS60混砂车输砂系统常见故障判断与处理

通过对XC-HS60混砂车输砂系统中出现的问题进行分析,提出了对输砂系统液压油温过高以及液压马达、电磁线圈等常见故障的解决方法,介绍了混砂车输砂系统使用和改造的一些经验。     

新型冻沙破碎机的计算机辅助设计

论述了一种新型冻沙破碎机的工作原理，通过对原始实验数据的采集，得出了破碎辊的转速，由此经过计算机计算得出了设计参数，从而完成最终的总装设计。     

The ricochet of spherical projectiles off sand

Plough development with time has been studied for the ricochet of 1 in. dia. spherical projectiles off sand for various entry speeds 0(10²) m/sec but with a fixed initial impact angle of 15°. Results show that retardations, of the order of 10⁵ m/sec², are associated with the penetration phase and that instantaneous longitudinal retardations are proportional to velocity squared; in the ascending phase retardations are very much smaller and the speed almost constant.The critical angle of ricochet is also shown to depend slightly on speed. For a 0·5 in. ball the critical angle reduces from 20° at 100 m/sec to 18° at 375 m/sec.     

Cavitation–silt erosion in sand suspensions

Cavitation–silt erosion in sand suspensions has elicited research attention. However, erosion characteristics in various conditions of liquids remain unknown due to their complex mechanisms. Thus, the effects of sand size, concentration, and temperature of sand suspensions on cavitation–silt erosion and viscosity were experimentally investigated in the present work. The findings proved the existence of critical sand size. The silt–cavitation erosion decreased with the increase of sand concentration when the sand was smaller than the critical size, and it increased with the increment of the sand size and temperature. A good relationship between the viscosity and the sand size, concentration, and temperature was determined. Moreover, the cavitation–silt erosion mechanisms were obtained on the basis of the viscosity and impingement erosion analysis standpoint.     

A cathodoluminescent study of quartz sand grains

Surfaces and cross sections of individual quartz sand grains have been examined in both the emissive and cathodoluminescent (CL) modes using a scanning electron microscope. The cathodoluminescent micrographs reveal sub-surface information not seen in the emissive mode micrographs. The CL features are generally associated with previous stressing, fracturing or abrasion of the grains, and are probably related to the formation of disrupted-lattice and/or amorphous quartz. The sequence of events during the formation of these features can be identified on many grains by studying the spatial distribution of the most common form of CL contrast—narrow dark bands. On other grains, irregularly distributed dark patches are generally observed to be a surface phenomenon, but the distribution, depth and intensity of these features can be studied by examining cross sections of grains. While it is common for the banded features to cross the entire specimen, it is rare for the diffuse areas to penetrate more than 30 μm. Some grains when experimentally heated above the α-β transition temperature show a marked change and even a complete reversal in CL contrast. Such studies of grains in cathodoluminescence can supplement the environmental information obtained from emissive mode micrographs of geological materials.     

铸铁件夹砂缺陷的防止

针对铸铁件中常见缺陷夹砂产生的机理，着重从造型、浇注工艺和操作方面介绍了防止夹砂缺陷的方法和措施。     

The abrasive wear of silica sand agglomerates

Processing of agglomerated particulate products can lead to attrition by abrasive wear as the agglomerates move relative to one another. In order to investigate this damage mechanism under controlled conditions, bar-shaped silica sand agglomerates of a range of strengths have been formed by addition of appropriate proportions of polyvinylpyrrolidone binder (molecular weight 44 000). These were then tested for wear resistance against various grades of abrasive paper and by rubbing against each other. In common with many materials, it was found that the wear rate is proportional to total sliding distance and to normal load, and independent of relative velocity. A simple Coulombic interlocking wear model is advanced to account for the dependence of wear rate on the size of abrasive particle forming the countersurface. In sustained (multi-pass) sliding, the presence of the debris reduces the attrition rate significantly. This phenomenon has been exploited by various workers who introduced solid lubricants into particle-processing devices in order to reduce attrition. The wear rate of agglomerates of different strengths has been found to be approximately proportional to the reciprocal of K_c, the critical stress intensity factor measured for the same bar agglomerates using the three-point bend test. This relationship between attrition rate and K_c has also been found for attrition in fluidized beds.     

防砂剂评价试验装置的设计

化学防砂作为油田防砂采油的手段之一,防砂剂起着至关重要的作用,防砂剂性能的好坏直接关系到化学防砂效果的好坏。随着防砂技术的不断进步。特别是在化学防砂剂的性能改进上。出现了很多新型的防砂剂。研制一套能对防砂剂进行有效评价的装置有很重要的现实意义。本文提出了设计一套通过对压力、温度以及采集砂样质量的测量实现对防砂剂性能进行评价的装置。该装置适用于对在同一压力、温度条件下对不同防砂剂性能进行评价,也适用于在不同温度压力条件下对同一防砂剂的性能进行评价。     

工业控制系统及其互操作研究

针对现有工业控制系统的互操作程度不高,通过分析工业控制系统的组成与分类,研究互操作技术的发展过程,给出使用opc实现工业控制系统互操作的实现框架,可以提高工业控制系统的互操作程度,指导制造企业工业控制系统的智能化发展。