The Application and Prospect of Stabilization/Solidification Technology for Hazardous Waste in China

The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related literature,this paper discussed the present situation about the treatment of the solid waste using stabilization/solidification technology;meanwhile we have a variety of outlooks on the future of the stabilization/solidification technology.

The Application and Prospect of Stabilization/Solidification Technology for Hazardous Waste in China

The number of hazardous waste in our country increased dramatically in recent years,stabilization/solidification technology begins to attract a wide spread attention by domestic scholars.Based on the domestic related literature,this paper discussed the present situation about the treatment of the solid waste using stabilization/solidification technology;meanwhile we have a variety of outlooks on the future of the stabilization/solidification technology.

Numerical prediction of the incremental melting and solidification process

A mathematical formulation is applied to represent the phenomena in theincremental melting and solidification process (IMSP), and the temperature and electromagneticfields and the depth of steel liquid phase are calculated by a finite difference technique using thecontrol volume method. The result shows that the predicted values are in good agreement with theobservations. In accordance with the calculated values for different kinds of materials anddifferent size of molds, the technological parameter of the IMS process such as the power supply andthe descending speed rate can be determined.

Microstructure control and hot cracking behavior of the new Ni-Co based superalloy prepared by electron beam smelting layered solidification technology

The prevention of hot cracking formation is of utmost importance in the production of the new Ni-Co based superalloys through the utilization of the electron beam smelting layered solidification technique(EBSL),as it ensures exceptional homogeneity and dependable consistency of the specimens.In contrast to previous studies that focused on minimizing the liquid film and solidification range,our methodology adopts a distinct approach.In this research,a novel methodology was employed to mitigate internal stresses through the implementation of equiaxed grain layers via an alternately reduced cooling method.This ultimately resulted in the elimination of hot cracking.To be more specific,the transition from a columnar to an equiaxed structure was observed during the layer-by-layer construction process in the fabrication of the new Ni-Co based superalloy in EBSL.The EBSL-Ni-Co superalloy,when subjected to the alternating reduction cooling method,exhibited an internal stress of 49 MPa.This value represents a significant reduction of 83.8%compared to the internal stress observed when employing the linear reduction cooling method.Additionally,the solvus temperature of theγ-γ’eutectic phases in EBSL-Ni-Co superalloys produced by the alternating reduction cooling method is significantly higher.Intriguingly,the Nth layer of the EBSL-Ni-Co based superalloys produced by EBSL simultaneously heats treated with the preceding layers.And the low melting point phase gradually dissolved back into the matrix.The implementation of an alternating reduced cooling method successfully mitigated the formation of the liquid film in theγ-γ’eutectic phase and the buildup of internal stresses in the EBSL-Ni-Co superalloy during its manufacturing process.These discoveries open up a novel preparation procedure pathway for the manufacture of crack-free superalloys with superior mechanical characteristics using EBSL.

Wafer level hermetic packaging based on Cu-Sn isothermal solidification technology

A novel wafer level bonding method based on Cu-Sn isothermal solidification technology is established. A multi-layer sealing ring and the bonding processing are designed, and the amount of solder and the bonding parameters are optimized based on both theoretical and experimental results. Verification shows that oxidation of the solder layer, voids and the scalloped-edge appearance of the Cu6Sn5 phase are successfully avoided. An average shear strength of 19.5 MPa and an excellent leak rate of around 1.9 × 10-9 atm cc/s are possible, meeting the demands of MIL-STD-883E.

The First China Foundry Scientific and Technological Achievements Fair was successfully held in Changsha

In order to promote transformation of scientific and technological achievements and development of scientific and technological service in foundry industry,change innovative achievements into real industrial activities and market profit,and create new growth sources,under the leadership of the Ministry of Science and Technology, the Productivity Promotion Center of Foundry Industry of China maximized resource advantages, fully integrated innovative resources, took market demands as guidance, built interconnected service platforms, supplied ＂one-stop＂ services for scientific and technological innovation in the foundry industry and the development of small and medium-sized enterprises.

新工科材料类人才培养中专业课程思政实践研究

辽宁科技大学新工科材料类人才培养过程中,以应用创新能力培养为核心,鼓励专业课教学实现产教融合。该文以金属凝固原理及技术课程为例,解析课程思政建设体系。基于人才培养目标,凝练出“凝心铸魂,发扬工匠精神,实现凝固技术智能化,打造无缺陷铸件”的课程主线。以家国情怀、职业素养等为一级维度,构建课程思政目标体系,建立课程思政二十条。以教学案例为载体,将课程思政写入大纲,融入课堂,践行立德树人的使命,提升学生自主学习内驱力,搭建理论与实践的桥梁,达成新工科应用创新型人才培养目标。

大掺量磷石膏路基填料的性能研究与工程应用

为探索大掺量磷石膏制备路基填料与填筑应用的可行性,开展了固化磷石膏路基填料的路用性能与浸出毒性试验,分析了磷石膏固化稳定机理。结果表明:经固化后磷石膏强度、水稳性均得到大幅提高,当固化剂掺量为2%时,试样28 d无侧限抗压强度为1.51 MPa、CBR值为65%、浸出液中的氟离子浓度为0.61~2.00 mg/L、总磷浓度<0.003 mg/L;以生成氟化物沉淀、磷酸盐沉淀化学稳定方式及水化凝胶产物(C-S-H、C-A-S-H)粘附包裹物理固化方式实现固氟除磷。填筑试验路应用验证表明,固化磷石膏路基的压实度、弯沉、回弹模量值、污染物浸出量均满足相关标准要求。

土壤修复一体机在重金属污染土壤修复中的应用

对于重金属污染土壤,固化稳定化技术具有效率高、修复周期短、普适性强等显著优势,是目前较为有效的修复技术。文章介绍了重金属污染土壤修复设备在工程应用中存在的问题,并介绍了XF150土壤修复一体机。该设备性能满足重金属污染修复的技术指标和要求,已成功应用于多个修复项目。

就地固化技术在牛田洋快速通道项目中的应用

针对汕头市牛田洋快速通道沿线软土深厚、周边环境敏感的特点,提出采用就地固化技术先对软土进行浅层处理,再结合排水固结法或复合地基法进行深层处理的联合处治方法,并给出固化土层质量检测标准。在大规模施工前选取局部路段对水泥掺量分别为3%、4%、5%的固化剂进行配合比试验,试验结果表明3种固化剂配合比均能满足设计强度和承载力要求,从统计结果看水泥掺量4%的固化剂表现最优。利用大规模施工过程中的质量检测数据作为样本进行相关性分析,得到固化土强度与龄期之间的关系,为同类项目就地固化设计时强度取值提供参考。

淤泥原位固化施工技术研究

海湾滩涂是我国重要的土地资源之一,其特殊的地理环境和地质条件给工程建设带来了极大的挑战。传统的淤泥处理方法存在诸多不足,无法满足现代工程建设的需要。通过对淤泥原位固化施工技术研究,探讨淤泥固化的技术原理,并根据环东海域新城埭头溪(下游段)综合治理工程B标段的应用情况,分析性能指标,确定其可行性,为类似工程提供技术借鉴和参考。

钻井废泥浆固化处理技术研究进展及展望

钻井过程会产生大量的废泥浆,而这些废泥浆会对环境造成严重污染。针对钻井废泥浆的污染特点,文章综述了当前固化处理的一些常用的处理技术,对各种处理方法中的技术优势和存在的主要问题进行了分析,并提出了钻井废泥浆处理的发展方向的建议。

喷射成形工艺的发展及应用

喷射成形是近年来发展较快的一种新型快速凝固技术 ,应用于多种高性能金属材料的制备中。介绍了该工艺的原理、特点、设备及在铝基、铁基、铜基和高温合金等不同材料中的研究及应用情况 ;对该工艺近几年在热传输、气体流场动力学、凝固组织形成机制和材料性能等理论方面的进展做了总结。并对该工艺存在的问题和今后的发展方向提出了一些新的观点。

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成 ,凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求 ,以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究 ,并介绍了其中某些方面和展望了可能的发展趋势。

ZA合金凝固技术的研究进展

ZA铸造合金强度高,耐磨性好,成为近年的研究热点之一。阐述ZA合金的凝固特点,综述了ZA合金凝固技术国内外的研究现状,概述采用压铸、挤压铸造、喷射成形、超高压凝固、过热处理、外场下凝固等凝固技术对ZA合金微观组织的影响规律,分析了各凝固技术的特点,并对ZA合金凝固技术的前景进行了展望。

OCC技术研究现状及其进展

ＯＣＣ技术从发明至今已有２０年的历史，目前已有３０家以上公司采用该技术开发出产品，在工业中获得广泛应用。评述了ＯＣＣ研究现状及其应用情况，并提出了在国内开展ＯＣＣ技术值得重视的几个问题。

大型齿轮圈铸钢件成型过程工艺优化

利用华铸CAE软件对大型齿轮圈铸钢件进行了凝固过程的数值模拟,发现了缩孔、缩松缺陷,确定了其产生的位置,分析了其产生原因及机理。在此基础上对其铸造工艺进行了修改,工艺优化,又一次进行凝固模拟,对前后模拟结果进行了分析与比较。结果表明,合理设置保温冒口、冷铁的大小和位置,加上合适的冒口套,可以保证铸件顺序凝固和金属液的有效补缩,获得结构完整、没有缺陷的铸钢件。

大型挂舵臂铸钢件铸造工艺优化

利用华铸CAE/Inte-CAST8.0软件对大型挂舵臂铸钢件进行了温度场的凝固模拟,预测了缩孔、缩松缺陷产生的部位,并且解释了形成机理,在此基础上通过对模拟结果进行分析,对其铸造工艺进行了优化。结果表明:合理设置保温冒口、冷铁的大小和位置,可以保证铸件顺序凝固,并且延长金属液的有效补缩距离,获得符合国际标准的挂舵臂铸钢件。

快凝AlFeVSi合金的高温退火行为

对比研究了冷变形前后的快凝ＡｌＦｅＶＳｉ合金高温退火时性能与显微组织的变化规律．结果表明，冷变形并未促进合金退火时的性能与组织变化，这可能与该合金表现出的低加工硬化效应，退火时位错大量增殖，弥散相对再结晶的阻碍以及冷变形态合金的退火硬化现象有关．粗化的弥散相与迁移的晶界是高温下位错增殖的主要来源．

大型磨台铸钢件的数值模拟与工艺优化

利用数值模拟软件ViewCast对某大型铸钢件磨台的凝固过程进行了数值模拟,预测了磨台产生缩孔缩松缺陷的位置。根据模拟结果初步设计了磨台的补缩系统工艺方案,对设计的工艺方案进一步模拟优化,获得了合理的补缩系统工艺方案,并在实际生产中,获得了良好的效果。