稀土钕对激光快速成形TC4合金组织及性能的影响

针对氢化脱氢钛合金粉末氧含量较高的问题，研究了添加稀土钕对激光快速成形TC4合金组织及性能的影响。结果发现，添加稀土Nd后，激光快速成形TC4合金的宏观晶粒尺寸变化不大；但随稀土添加量的增加，初始β列状晶逐渐转化为全β等轴晶，晶粒内部的魏氏α组织逐渐转变为网篮α，粗化α条不断增多，呈现团束聚集趋势，晶界α集束体积分数也不断增大；随稀土添加量的增加，激光快速成形TC4合金的室温塑性先大幅度提高，然后急剧降低；稀土添加量为0．1％～0．2％（质量分数，下同）时，氧含量为0．26％的氢化脱氢TC4合金粉末激光快速成形件沉积态的抗拉强度达975MPa，延伸率9．5％，满足锻件标准要求。     

250kW炉底升降式电阻炉设计简介

介绍了新设计炉子的总体结构和主要参数；对炉子中的升降机构，电热元件，砌砖体等部分的设计构想和结构特点分别作了阐述。炉子经过制造和使用表明，制作容易，维修方便，使用性能良好。     

CREEP BEHAVIORS OF Pt-RE ALLOYS AT HIGH TEMPERATURES

The creep behaviors of Pt-RE alloys have been studied at 1200℃ and 1400℃.The results show that asmall amount of RE elements improves the creep behaviors of platinum greatly.The creep behaviors of PtGd0.5,PtLa0.5 and PtLa0.3 Gd0.2,are best among all the alloys studied.As far as the creep behaviors are concerned,the traditional heat-resistance alloy PtGd10 can be replaced by PtGd0.5.Particularly,the properities of PtGd0.5are near to those of PtRb10.For most of the Pt-RE alloys,long-time,static,super high-temperature treatment inair is of no advantage to the creep rupture life.The mechanisms of the effects of rare-earths on high-temperaturecreep properties of platinum are discussed.     

含钴锆基块状非晶合金的制备与力学性能

采用水淬法制备了Zr—Ti—Cu—Ni—Be—Co块状非晶合金(BMGs)。使用XRD进行相分析，采用热分析仪进行玻璃转变温度、晶化温度和热稳定性等的测定，用SEM观察试样压缩后的外表面和断口形貌。研究了Co对Zr—Ti—Cu—Ni—Be合金非晶形成能力(GFA)、热稳定性及力学性能的影响。结果表明：含Co的所有Zr—Ti—Cu—Ni—Be BMGs都有1个明显的玻璃转变点和宽的过冷液相区(△T）。Zr38Ti17Cu10.5Co12Be22.5合金具有和Zr41Ti14Cu12.5Ni10Be22.5合金相当的△T；Co的添加明显提高Zr—Ti—Cu—Ni—Be BMGs的力学性能，含Co量大于10at％的Zr—Ti—Cu—Ni—Be BMGs的压缩断裂强度（σf）超过2000MPa，Zr38Ti17Co22.5Be22.5合金的σf达到2230MPa，比Zr41Ti14Cu12.5Ni10Be22.5合金的σf提高23％。     

ZL105合金悬浮铸造工艺研究

对ZL105合金悬浮剂的制备、加入量、加入方式、加入温度及熔化时间等悬浮铸造工艺进行了初步探讨。结果表明,ZL105合金采用恳浮铸造简单易行,而且对减小体收缩、细化晶粒组织、降低壁厚对晶粒组织的敏感性以及提高针孔度级别有明显效果。     

基于特征的派生式车身覆盖件冲压CAPP的研究

本文介绍了一种基于特征的派生式车身覆盖件冲压工艺ＣＡＰＰ系统。通过建立特征模型，引入成组技术，建立工艺数据库，系统的功能得以实现。该系统保证了车身开发中ＣＩＭＳ的信息集成。     

Thermal cross-linking and anti-meltdrop properties of copolyester containing phosphorus/magnesium salt composites by in situ polymerization

Polyester is widely used in household products because of its good mechanical properties and wears resistance, but polyester is easy to ignite and inclined to produce droplet, so its application range is limited. The cross-linkable magnesium hydroxide nanoparticles were incorporated into flame-retardant polyester, which enables the phosphorus-containing copolyester with thermal cross-linking and anti-meltdrop properties. The nanoparticles were achieved by in situ polymerization and acted as a nucleating agent for improving the crystalline properties of the copolyester. Furthermore, the nanoparticles also enhanced anti-meltdrop properties and reduced the heat and gas release during the combustion process of the copolyester. The maximum heat release rate and total smoke release reduced by 39.8% and 74.4% compared with pure polyester. Specifically, the combustion products of the nanoparticles and phosphorus flame retardant could act a barrier role by covering the carbon layer to isolate air and heat, thereby resulting in excellent anti-meltdrop properties. The simple modification method reported here realizes the collaborative modification of flame retardant and anti-meltdrop properties of phosphorous flame-retardant copolyesters by thermal cross-linking.     

Preparation of β-cyclodextrin/SBS modified asphalts for the improvement of anti-aging,rheological property,and storage stability

Styrene-butadiene-styrene (SBS) modified asphalt (SMA) has been widely used in road engineering for decade. However, the phase separation of SMA was obvious during the transport and SBS degraded after aging. To resolve these problems, β-cyclodextrin (β-CD) was used to modify SMA in this work. Conventional properties, storage stability, the effect of short-term aging on the morphology, and rheological property for SMA and β-CD/SMA were investigated. The softening point of modified asphalt reached to the maximum of 66.7°C when 1 wt% β-CD was added to SMA, where the penetration had shown the minimum of 80.8 dmm. In addition, the ductility of β-CD/SMA increased to the maximum of 797 mm when the content of β-CD was increased to 5 wt%. Furthermore, incorporation of β-CD improved the storage stability of SMA. Importantly, the aggregation of SBS was observed in β-CD/SMA, but modifiers distributed uniformly after a short-term aging. The rutting resistance and antiaging performances of SMA were also improved by the addition of β-CD. Considering the comprehensive properties of modified asphalt, the optimum content of β-CD was found to be 2 wt%.     

A power fluctuation evaluation method of PV plants based on RankBoost ranking

Fluctuation evaluation is an important task in promoting the accommodation of photovoltaic (PV) power generation. This paper proposes an evaluation method to quantify the power fluctuation of PV plants. This consists of an index system and a ranking method based on the RankBoost algorithm. Eleven indices are devised and included in the index system to fully cover diverse fluctuation features. By handling missing and invalid data effectively, the ranking method fuses multiple indices automatically and provides a systematic and comprehensive comparison of power fluctuation. Simulation results based on power data from six PV plants indicate that the evaluation list obtained by the RankBoost ranking method is better represented and more comprehensive than that derived by the equal weight method.     

双色挤塑成型

以彩色毛笔杆为例 ,分析了双色挤塑成型的基本原理 ,介绍了设计制造双色挤塑成型简易设备的方法。