金属粉末注射成形生产设备及其发展趋势

根据金属粉末注射成形技术的特点,介绍了金属粉末混炼、注射、脱脂、烧结、后处理各工序所使用的各生产设备的原理及其应用。阐述了金属粉末注射成形工业生产设备的最新研究动态,提出了其主要发展趋势。     

金属粉末注射成形技术及其数值模拟

金属粉末注射成形技术可以大批量、低成本地制造高性能异形精密零部件,是当前先进制造技术领域研究的热点之一.本文概述了金属粉末注射成形的工艺,包括粉末制备、粘结剂选取、混料、注射以及后续的脱脂、烧结,介绍了金属粉末注射成形的发展过程、现状及新工艺,深入分析了金属粉末注射成形数值模拟,在此基础上展望了金属粉末注射成形的发展趋...     

浅谈金属粉末注射成形技术

金属粉末注射成型技术是一门新型近终成型技术。它是利用模具可注射成型坯件并通过烧结快速制造高密度、高精度、高强度、三维复杂形状的结构零件。针对发展金属粉末成形技术成为新热点,介绍了金属粉末成形的优势、工艺特点及应用,分析了金属粉末成形的主要原材料,提出了金属粉末成形的混炼和烧结工艺。     

钛及钛合金金属粉末注射成形技术的研究进展

钛及钛合金兼具低比重、高比强度、优异的生物相容性和良好的耐腐蚀性,在航空航天、生物医疗、化工、汽车等领域有极大的应用潜力。钛及钛合金金属粉末注射成形技术(metal injection molding,MIM)能够实现中小型复杂形状钛产品的大批量、低成本制备,对于推动钛及钛合金产品的生产及应用具有重要意义。本文介绍了金属粉末注射成形钛及钛合金的特点及优势,从粉末原料、黏结剂体系、粉末注射成形、脱黏和烧结等方面综述了钛及钛合金金属粉末注射成形技术的研究进展,并针对目前存在的主要问题,分析了金属粉末注射成形钛及钛合金的研究方向及发展前景。     

金属粉末注射成形技术概述

金属粉末注射成形技术是当今最热门的零部件成形技术。适于制作形状复杂，性能高的产品，且生产成本低。本文简要概述了金属粉末注射成形生产工艺过程技术特点，研究现状和进展及产业化状况，指出了其今后研究重点。     

金属粉末注射成形技术的现状和发展动向——Ⅲ.发展动向

综合阐述了金属粉末注射成形(MIM)的技术现状和产业化发展状况,并从粘结剂的选择和优化设计、新型粘结剂的开发和实用化、脱脂模型和脱脂动力学研究、尺寸精度过程控制几个方面评述了金属粉末注射成形技术重要的发展动向。     

轿车用注射成形粉末冶金零件通过验收

由山东金洲集团乳山金珠粉末注射制造有限公司研制开发的“九五”国家科技攻关计划“轿车用注射成形粉末冶金零件”于 2 0 0 0年 12月 2 3日通过了由山东省科技厅组织的专家验收。据山东金洲集团董事长、总经理李振江介绍 ,轿车用注射成形粉末冶金零件 ,是利用金属粉末注射成形技术 ,将注射成形粉末冶金材料应用于轿车零件 ,拓宽轿车零件的制造工艺 ,提高了小型、复杂零件的生产效率 ,节约原材料 ,增加经济效益 ,有力地支持了我国轿车工业的发展。此次通过的研究表明 ,金属粉末注射成形技术得到了进一步发展 ,特别是生产工艺更加成熟、稳定 …     

注射成形金属粉末零件

本文详细叙述了目前金属粉末注射成形的具体工艺过程,在过程中使用各种不同方法的优缺点;金属粉末注射成形零件的设计参数和它与普通成形方法相比较的竞争性。     

金属粉末微注射成形技术的发展

本文综述了金属粉末微注射成形技术(Micro MIM)的基本概念、特征、优势,简要叙述了Micro MIM技术的最新动态,包括Micro MIM的工艺特点,各工序的技术、设备等要求,数值模拟,研究现状,应用领域等。     

Fe-2Ni金属粉末注射成形工艺评述

金属粉末注射成形技术是当今最热门的零部件成形技术。适于制作复杂形状产品,性能高,成本低。本文简述了Fe-2Ni注射成形的工艺过程,综述了其研究现状和性能水平。作者认为:粗粉注射成形研究、快速脱脂工艺研究以及尺寸精度控制研究将是研究热点和重点。     

3200m~3高炉喷吹系统工艺优化与改进

针对邯宝炼铁厂高炉喷吹系统存在的诸多问题,对喷煤工艺进行了改进和操作优化,彻底解决了喷吹启动困难的问题,减小了喷吹脉动现象,提高了装煤速度和喷吹能力,增强了喷煤保障性,满足了高炉喷煤量的要求,最大喷煤比已达150 kg/t以上。     

精炼钢包狭缝喷粉水模型研究

鉴于对狭缝式钢包底吹喷粉新工艺缺乏相关的研究,则采用往水模型的水溶液中喷吹氯化钠粉剂来研究狭缝在不同条件下对钢包喷粉精炼效果的影响。结果表明：减小狭缝的宽度有利于提高喷粉的有效利用率;狭缝喷粉的有效利用率高于圆孔喷粉;偏心底和侧部喷粉的有效利用率高于中心底喷粉;在底喷粉条件下,狭缝喷粉的有效利用率随空塔速度的增大而先增加后减小,并存在一个最佳的空塔速度。     

冶金用喷粉罐喷粉速率控制的冷态模拟试验

 为实现冶金用喷粉罐喷粉速率的稳定控制，通过冷态模拟试验，测定喷粉罐不同喷吹参数对罐内压力和输粉管路压力的影响规律，研究了罐内压力与输粉管路压力的差值Δp对喷粉速率的控制规律。研究结果表明，正常喷粉状态下，罐内压力主要由罐顶充压和流化气压力共同决定。输粉管路压力主要由载气流量决定，其值随载气流量的增大而增大。通过设置罐顶充压、流化气压力和载气流量的不同参数组合来改变Δp，可实现对喷粉速率的稳定控制。在载气流量相同条件下，喷粉速率随Δp的增大而增大；在Δp相同条件下，载气流量值越大，喷粉速率越大。     

Stability and compatibility of granisetron hydrochloride in i.v. solutions and oral liquids and during simulated Y-site injection with selected drugs

The stability and compatibility of granisetron hydrochloride in common i.v. fluids and oral liquids and during simulated Y-site injection with selected drugs were studied. One milliliter of solution containing granisetron 1 mg (as the hydrochloride salt) was added to 50 mL of 5% dextrose injection, 5% dextrose and 0.9% sodium chloride injection, 5% dextrose and 0.45% sodium chloride injection, or 0.9% sodium chloride injection in polyvinyl chloride (PVC) bags and to 5 mL of 5% dextrose injection, 0.9% sodium chloride injection, or bacteriostatic water for injection in polypropylene syringes and stored at room temperature (20 degrees C) for 24 hours. One milliliter of the granisetron hydrochloride injection was added to 50 mL of apple juice, orange juice, cola, or an electrolyte replacement solution and stored for 60 minutes at room temperature. Twenty-nine drugs were mixed with the granisetron hydrochloride injection in 0.9% sodium chloride injection in volumes simulating Y-site injection and stored at room temperature. Finally, dexamethasone sodium phosphate injection 0.5 mL and 1 mL of the granisetron hydrochloride injection were added to 50 mL of 0.9% sodium chloride injection in a PVC bag and stored for 60 minutes. Drug concentrations were determined by high-performance liquid chromatography, and color, clarity, and pH were evaluated. Granisetron hydrochloride was stable in and compatible with all the i.v. solutions and oral liquids. Neither granisetron nor any of the drugs it was tested with during simulated Y-site injection showed any physical changes except for a slight Tyndall effect in the granisetron hydrochloride-doxorubicin hydrochloride combination; all the drugs retained at least 96% of initial concentrations. Granisetron and dexamethasone sodium phosphate were stable and compatible in the admixture. Granisetron 1 mg (as the hydrochloride salt) was stable for 24 hours in four i.v. infusion fluids in PVC bags and in 5% dextrose injection, 0.9% sodium chloride injection, and bacteriostatic water for injection in polypropylene syringes; for 1 hour in four oral liquids; for 4 hours in the presence of each of 29 drugs during simulated Y-site injection; and for 1 hour when mixed with dexamethasone sodium phosphate in 0.9% sodium chloride injection in a PVC bag.     

Changes in the brain monoamine metabolism in acute liver failure produced by ischemia-reperfusion injury in rats

Ninety-five patients with 107 trigger digits were divided into 2 groups and studied prospectively to evaluate steroid injection placement and efficacy. In 1 group, an attempt was made to deliver 1 injection into the tendon sheath at the A1 pulley. In the other group, 1 injection infiltrated the subcutaneous tissues overlying the A1 pulley. Radiopaque dye provided contrast to the injection medium, and postinjection x-rays identified the true delivery site of the steroid solution. Of the 52 digits into which intrasheath injection was attempted, 19 digits (37%) received all the injection within the sheath, 24 (46%) received medication into both the sheath and the subcutaneous tissues, and 9 (17%) received no medication within the tendon sheath. The results were analyzed to determine whether injection placement influences the efficacy of steroid injection. The confirmed all-sheath injection group exhibited a 47% good response, the mixed sheath and subcutaneous group had a 50% good response, and the all-subcutaneous group had a 70% good response. The results of this study suggest that true intrasheath injection offers no apparent advantage over subcutaneous injection in the treatment of trigger digits.     

Drug distribution in the vitreous humor of the human eye: the effects of intravitreal injection position and volume

PURPOSE: The purpose of this study was to determine how the position and volume of an intravitreal injection affect the distribution and elimination of drug from the vitreous humor. METHODS: A mathematical model that had been developed and used previously to study drug distribution in the vitreous humor of the rabbit eye was modified to match the physiology of the human eye. Fluorescein and fluorescein glucuronide were used as the model compounds for these studies. Four extreme injection locations were considered: a central injection, an injection displaced towards the retina, an injection displaced towards the lens, and an injection displaced toward the hyaloid membrane. Injections containing an equal mass of drug dissolved in volumes of either 15 microL or 100 microL were compared. RESULTS: The location of an intravitreal injection was found to have a substantial effect on elimination and distribution in the vitreous. Peak concentrations at different vitreous locations varied by over three orders of magnitude, depending on the injection location. The mean concentration of drug remaining in the vitreous 24 hours after the intravitreal injection varied by up to a factor of 3.8, depending on the injection location. Changing the volume of the injection from 15 microL to 100 microL dampened the effects of the initial injection location; however, meant concentrations at 24 hours still varied by up to a factor of 2.5. CONCLUSIONS: Careful control of the conditions of an intravitreal injection could reduce treatment variability, improve bioavailability, and reduce the possibility of retinal toxicity.     

太钢1800m~3高炉喷煤系统设计及运行

太钢3号高炉喷煤系统采用三罐并列、喷吹主管加分配器的喷吹形式,喷吹装置最大喷吹能力为煤比250kg/t。主要特点：三罐并列喷吹计量准确;采用浓相喷吹,实现了对氮气的回收;使用两段式喷枪、一键式全自动操作等。喷吹系统2007年8月投产,平均煤比180kg/t以上,个别月份达到200kg/t。经过两年的生产实践证明,该系统设计合理,一直处于良好的运行状态。     

工艺参数对注射成形各向异性粘结NdFeB磁体性能的影响

研究了注射温度、模具温度、注射压力及注射速度对注射成形各向异性粘结NdFeB磁体的磁性能及力学性能的影响，并分析了其原因。结果表明：注射温度及模具温度对磁体磁性能影响较大，而注射压力则对磁体的抗压强度影响较大。在最佳的注射参数下，获得了最大磁能积和抗压强度分别为90kJ／m^3及130MPa的高性能粘结磁体。     

Effect of metoclopramide, ranitidine, and droperidol on the lower sphincter of the esophagus. Experimental study on the opossum (Didelphis albiventris)

Electromanometric measures of the gastroesophageal junction were performed in 20 adult, male and female, anesthetised opossums. The electromanometric examinations were performed according the intermitent pull through technique. The research was divided in four groups, according to the drug to be analysed: group 1 (20 animals) IM injection of physiological solution (control group); group 2 (20 animals) IM injection of metoclopramide; group 3 (20 animals) IM injection of ranitidine; group 4 (20 animals) IM injection of droperidol. Electromanometry was done 15 minutes before the drug injection, just after the injection and 15, 30, 45 and 60 minutes after the injection. In each one of the moments the pressure of the lower esophageal sphincter (LES-mmHg) was analysed. Considering LES pressure the results observed were: in group 1 it was not observed any significative alteration after IM injection of physiologic solution; in group 2 it was observed significative pressure increase, 15 minutes after metoclopramide IM injection; in group 3 it was observed pressure increase, being significative at 15 and 30 minutes after IM injection; in group 4 it was observed significative increase in LES pressure in every moment, 15 minutes after droperidol IM injection.     

A study on behavior towards injection among residents and physicians in Kaohsiung & Ping-tung area

To understand why people in Taiwan preferred iatrogenic injection as their medical therapy, we surveyed the knowledge, attitude, and behavior of iatrogenic injection for people and doctors in Kaohsiung and Ping-tung area by questionnaire. The results of the survey are drawn below: 1. More than 91.7% of the interviewed people would like to receive iatrogenic injection as their medical therapy, and 78.1% of the parents would choose iatrogenic injection for their children. The reason majority were because doctors suggested that and the parents believed iatrogenic injection is a quicker way of recovery. 2. In this study, 72.1% of the people received injection as their usual mode of medical treatment, and 74.9% of them had received injection during the previous month. When they brought their children to the clinics, the percentages of the above two conditions were 60.4% and 59.7% respectively. The factors influencing the reception of injection for people were the efficacy of the injection, education level and medical insurance. The influencing factors for children were the parents' medical behavior and the parents' willingness to accept injection. 3. About 83% of the interviewed doctors preferred iatrogenic injection as treatment for their patients. Almost 60% of them agreed that more patients would receive injection after National Health Insurance. About 72% of the doctors would not change the treatment for their patients, no matter how the system of the medical insurance changes. They would choose the right treatment for the distinct disease.