低温固体渗硼的渗层形貌与元素的再分布

利用Ｘ射线衍射仪、电子探针研究了低温固体渗硼的渗层形貌、相组成和元素的再分布特征。结果表明，低温固体渗硼的硼化层是由ＦｅＢ、Ｆｅ２Ｂ、Ｆｅ３（Ｃ，Ｂ）、Ｆｅ３（Ｓｉ，Ｂ）等相组成。硼化层的前沿无过渡区，ＦｅＢ和Ｆｅ２Ｂ生长过程中排挤出来的碳和硅没有发生远程扩散，而是就近形成Ｆｅ３（Ｃ，Ｂ）和Ｆｅ３（Ｓｉ，Ｂ）等形式的含碳和硅的硼化物。     

复合变质剂对Al—Si—Cu合金质效果的研究

借助扫描，电子探针等手段，对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金，加入Ｋ２ＴｉＦ６＋ＮａＢＦ４＋ＮａＦ＋ＮａＣｌ变质剂的变质效果进行了研究。实验结果表明，合金中加入该变质剂，不仅获得完全的变质组织，而且变质效果稳定。     

复合变质剂对Al－Si－Cu合金变质效果的研究

借助扫描、电子探针等手段，对Ａｌ－Ｓｉ－Ｃｕ亚共晶铸造合金，加入Ｋ２ＴｉＦ６＋ＮａＢＦ４＋ＮａＦ＋ＮａＣｌ变质剂的变质效果进行了研究。实验结果表明，合金中加入该变质剂，不仅获得完全的变质组织，而且变质效果稳定。     

稀土对固体渗硼剂渗硼扩散激活能的影响

文章介绍一种新型固体渗硼剂，采用固体粉末法对T8钢进行渗硼试验，并分析了稀土元素对该固体渗硼剂渗硼扩散激活能的影响。结果表明，稀土能增大硼的扩散系数，降低硼的扩散激活能，具有显著的活化催渗作用。     

硼砂型固体渗硼剂的应用

探讨了石墨粉加入大量对硼砂型固体渗硼剂结块的影响。结果表明，石墨粉加入量与渗剂中其它成分有关，但不能低于１５％。所研制的渗剂渗后不结块，工件表面清洁，能获得单一的Ｆｅ２Ｂ相渗层。工件淬火后渗硼层不开裂、不脱落，有优良的抗高应力磨粒磨损性能。用本渗剂处理的耐火砖模具，使用寿命可提高２￣３倍。     

渗硼层中夹缝组织的研究

对渗硼层中的夹缝组织进行了分析研究。结果表明：夹缝组织是渗硼层中的反常组织，硬度在３７０－５３０ＨＶ之间；主要成分为Ｆｅ，Ｓｉ，Ｃ，无Ｂ；相组成为ＦｅＳｉＣ，Ｆｅ３Ｓｉ和ＦｅＳｉ。对夹缝组织的形成原因进行了讨论。     

含稀土元素渗硼剂渗硼工艺试验

介绍一种含稀土元素廉价的固体渗硼剂，并对其进行了渗硼工艺试验。结果表明：采用该渗硼剂是可行的，且稀土可提高渗硼速率。     

RE—I2对固体深层渗硼催渗作用的研究

介绍了ＲＥ－Ｉ２复合对固体深层渗硼催渗的作用。结果表明，在固体深层渗硼剂中添加ＲＥ－Ｉ２有明显的催渗作用，不但可提高渗速，而且渗硼层厚度也明显增厚。初步探讨认为，ＲＥ－Ｉ２的催渗作用主要受两方面因素的影响，即（１）被渗金属表面应有活性ＲＥ、Ｉ２原子源；（２）ＲＥ－Ｉ２的复合效应能使基体晶体更容易产生畸变。     

含稀土固体渗硼剂渗硼处理试验

本文介绍一种廉价含稀土固体渗硼剂，并进行了渗硼处理试验，通过渗层组织的观察和渗层硬度的测定以及渗硼剂重复使用性的探讨。结果表明：采用该渗硼剂可使钢件表面获得较好的渗硼层，且稀土可以提高渗层的质量。     

固体渗硼中活性剂的选择

本文对固体渗硼中活性剂的选择作了系统的对比试验，认为不同的供硼剂对活性剂具有选择性，对某些供硼剂，两种或两种以上的活性剂以一定比例混合使用会起到比单个活性剂更垢催渗效果，硼砂来源广，价值便宜，作为供硼剂，可大幅度降低渗硼成本。     

硼砂型膏剂渗硼剂的研制

使用硼砂作为渗硼膏剂的供硼剂，对7种活化剂的活化效果进行了研究，发现活化剂的类型和自身熔点的高低对活化效果有影响，氟化物活化效果好于氯化物，熔点高的活化剂活化效果较好，几种活化剂配合使用渗速明显高于单独使用一种活化剂的渗速，利用正交试验法，确定了CaF2,MgCl2和Na3AlF6三种活化剂的最佳配比，所研制的MSG膏剂渗速快，渗层质量好，对碳钢和低合金钢均有良好的渗硼能力。     

稀土对一种固体渗硼剂渗硼动力学的影响

采用固体粉末法对40Mn2钢进行渗硼试验,分析了稀土元素对该固体渗硼剂渗硼动力学的影响,结果表明,稀土能使硼的扩散系数增大59％,使硼的扩散激活能降低4520．31J／mol,有效地提高了渗硼速度。     

固体渗硼时硼砂型渗剂中活性硼原子输运方式研究

设计了3种不同的装罐方法，通过改变试样与渗剂的接触方式，对固体渗硼时渗剂中活性硼原子输运到试样表面的方式进行了研究。结果表明，固体渗硼时，渗剂中有BF2和BF3气体生成，活性硼原子通过BF2在试样表面的吸附和分解以及在渗剂中的直接扩散这样两种方式输运至试样表面．其中活性硼原子在渗剂中的直接扩散是主要输运方式。BF2在渗硼中的主要作用是充当了还原剂的作用，通过它和BF3间的循环反应，将硼砂中的氧化硼源源不断地还原成活性硼原子，同时它在渗剂中的吸附和分解也加快了渗剂中活性硼原子的生成速度。     

基于扩散模型的低中碳钢渗硼动力学研究

为了研究含碳量对低、中碳钢的渗硼动力学的影响,将纯铁、20钢、40钢和50钢分别在850℃、880℃、910℃和940℃保温3 h、5 h、7 h和9 h进行粉末渗硼。采用面积法测量了渗层厚度。以基本的扩散定律和物质守恒定律等为基础建立硼的扩散模型,计算了低中碳钢渗硼过程中硼原子的扩散激活能和扩散系数。结果表明:渗硼层组织为锯齿状;渗层厚度随时间呈抛物线变化;随着钢的含碳量的增加,硼原子的扩散激活能增大,纯铁中硼原子的扩散激活能为151 kJ/mol,20钢中为159 kJ/mol,40钢中为168 kJ/mol,而50钢中为176 kJ/mol。     

Boride coatings obtained by pack cementation deposited on powder metallurgy and wrought Ti and Ti-6Al-4V

Wear resistance of Ti alloys needs to be improved, and an effective way to achieve this is through surface treatment. Boronizing is a surface treatment in which boron diffuses into the surface of Ti leading to the formation of hard and wear-resistant Ti borides. Boronizing of wrought and/or cast Ti alloys by pack cementation has been studied, while similar coatings on Ti alloys produced by powder metallurgy (PM) have not been reported. Also critical process parameters for boronizing Ti alloys, such as pack cementation powder composition and the process temperature have not been systematically studied and analysed. The present work reports on the surface modification of PM Ti and PM Ti-6Al-4V by boronizing, and presents some important thermodynamic aspects of the process comparing it with similar coatings applied to wrought Ti-6Al-4V. The coatings were characterised using scanning electron microscopy and X-ray diffraction. For both Ti and Ti-6Al-4V alloys the use of amorphous B as a B element supplier in the boriding powder pack led to the formation of a uniform external boride layer, while the use of B₄C as a B element supplier in the pack and under the same boronizing conditions, led to the formation of an external TiN layer and an internal layer containing B. The thermodynamic calculations performed proved successful in determining the appropriate conditions for boride coating deposition and estimating the phases likely to be formed. Finally the effect of surface roughness on the coating quality is discussed.     

CO2-Na2SiF6水玻璃砂工艺参数的确定

通过正交试验，研究了各种工艺对ＣＯ２－Ｎａ２ＳｉＦ６联合硬化水玻璃砂性能的影响。试验结果表明：对初强度的影响从大到小为吹气时间、水玻璃模数；对２４ｈ后终强度的影响从大到小顺序依次为模数、吹气是ａ２ＳｉＦ６状态、Ｎａ２ＳｉＦ６加入量；Ｎａ２ＳｉＦ６加入量与混砂工艺、吹气时间对性能存在交互影响。据此确定了最佳工艺参数。     

The Effect of Boronizing on Metallic Alloys for Automotive Applications

In this study the wear resistance, corrosion resistance, and oxidation resistance of boronized metallic alloys were investigated. Thermochemical treatment was performed by powder pack boronizing process at temperature 850-950 °C for 4 h. Saw-tooth morphology and smooth interface microstructures were observed with an optical microscope; microhardness was measured across the coating depth. The phases present in the boron coatings depend on the substrate material. High-temperature oxidation resistance was investigated and it was found that boron coating on ferrous alloys can resist temperatures up to 800 °C. The corrosion resistance of the boronized samples was improved and the corrosion rate was calculated for boronized and plain specimens. Wear testing was conducted by following the procedures of ASTM G99, ASTM D2526, and ASTM D4060. The obtained experimental results revealed that boronizing significantly improves the wear-resistance, corrosion-resistance, and oxidation resistance of metallic alloys. This article was presented at Materials Science & Technology 2007, Automotive and Ground Vehicles symposium held September 16-20, 2007, in Detroit, MI.     

Improving the surface hardness and wear resistance of Ti3SiC2 by boronizing treatment

In order to modify surface properties of Ti₃SiC₂, boronizing was carried out through powder pack cementation in the 1100-1400 °C temperature range. After boronizing treatment, one mixture layer, composed of TiB₂ and β-SiC, forms on the surface of Ti₃SiC₂. The growth of the coating is processed by inward diffusion of boron and obeys a linear rule. The boronizing increases the hardness of Ti₃SiC₂ from 3.7 GPa to a maximal 9.3 GPa and also significantly improves its wear resistance.     

冷塑性变形对45钢硼铬稀土共渗的影响

利用金相显微镜和扫描电镜观察及显微硬度测试,研究了冷塑性变形对45钢硼铬稀土共渗的影响.结果表明,经冷塑性变形后,硼铬稀土共渗速度明显加快,冷变形量越大,渗层深度越深.与此同时,渗层仍保持了较高的硬度和低的脆性.分析认为,冷塑性变形可使位错等缺陷增加,有利于硼原子的吸收与扩散.     

固体渗硼技术的研究与应用

回顾了渗硼技术的历史,介绍了固体渗硼技术的理论和实践,包括渗硼机制,钢铁渗硼层的组织和性能,冷作模具钢、热作模具钢、不锈钢、耐热钢的固体渗硼,以及固体渗硼技术在某些零件上的应用.