工业缝纫机梭床耐磨性研究

分析了缝纫机梭床磨损失效原因。论述了Ni-P化学镀表面技术应用于缝纫机梭床上的可行性。借助扫描电镜、能谱仪、磨损试验机、显微硬度计等设备对化学镀层的表面状态、组织结构及性能进行综合分析。结果表明，Ni-P化学镀层的硬度、耐磨性远远高于碳氮共渗层。其中Ni-P-SiC化学复合镀层的性能最好。同时对化学镀层的高硬度、高耐磨性进行了分析说明。     

The Study of Plasma Nitriding of AISI304 Stainless Steel

This paper presents results on the plasma nitriding of AISI 304 stainless steel at different temperatures in NH3gas. The working pressure was 100～200 Pa and the discharge voltage was 700～800V. The phase of nltrided layer formed on the surface was confirmed by X-ray diffraction. The hardness of the samples was measured by using a Vickers microhardness tester with the load of 50g. After nitriding at about 400℃ for two hours a nitrided layer consisting of single γN phase with thickness of 51.tm was obtained. Microhardness measurements showed significant increase in the hardness from 240 HV (for untreated samples) up to 950 HV (for nltrided samples at temperature of 420℃). The phase composition, the thickness, the microstructure and the surface topography of the nltrided layer as well as its properties depend essentially on the process parameters.     

低碳钢箔片氧化原因探讨

介绍了用低钢箔片（挂片）在对Unicase密封箱式炉进行炉内碳势定碳分析时存在被氧化的情况。经过分析后认为低碳钢箔片的氧化（除操作失误外）是由于以下两种原因造成：（1）箔片在冷却腔冷却过程中其腔内的温度下降导致压力下降，从而空气进入冷却腔，而此时箔片的温度尚未冷却到200℃以下，箔片发生氧化。（2）由于冷却水的作用，使冷却腔的温度降至露点以下，冷却腔内气氛（与炉内气氛相同）中的水蒸气被凝结，液态的水对炽热的箔片造成了氧化，在此基础上，提出了改进措施。     

Effect and mechanism of diphosphonic acid on flotation characteristic of fersmite and intergrowth gangue

1　INTRODUCTIONThereservesofniobium containingmineralsinChinatakethesecondplaceintheworld ,anddis tributemainlyinBaiyuneboofInnerMongolia ,TaimeiofGuangdongProvinceandYichunofJiangxiProvince ,etc .Niobium containingmineralsweredis coveredover 130kinds ,butonlyafewofthemhadindustrialvalue .Fersmiteisoneoftheseveralvaluedindustrialniobium containingminerals[1,2 ] .Theprocessingofniobium containingmineralsistoodifficultduetotheirfinesizeandnumerousspeciesandcomplexcomposing .Inmiddleperi…     

超音速火焰喷涂涂层抗高温氧化和耐冲蚀性能

采用超音速火焰喷涂（HVOF）技术喷涂WC涂层，并对其抗高温氧化和耐冲蚀性能进行测定。试验结果显示，与基体1Cr12W1MoV比较，HVOF制备的WC-17Co、WC-12Co、NiCrBSi＋35WC涂层具有非常良好的抗高温氧化和耐冲蚀性能。其中WC-17Co涂层在任何冲蚀角度下均表现出优良的抗冲蚀能力，是一种理想的汽轮机高压部件防护涂层。     

变形Fe-Nb-C合金的室温至180℃内耗

测量了700℃，30min水冷后变形Fe－Nb-C合金室温至180℃的内耗，发现除Snoek峰外，合金在此温度区还有阻尼峰。测量了合金经过980℃，2h中间处理样品的内耗，并给出变形及室温原位时效的汽车钢ST14与GBPH340的内耗结果。认为Fe-Nb-C合金的变形“B”峰。是被饱和Cotterll气团碳原子团簇钉扎的位错段拖曳碳的稀Cottrell气团运动引起的，是合金在变形时碳原子稀Cottrell气团择优分布在位错上的结果。     

利用自蔓延高温合成工艺在铸钢表面制备TiC/Fe复合材料层

在干砂消失模铸造模样表面涂敷一层经压实的自蔓延高温合成（SHS）粉料（Ti粉、C粉、Al粉、Fe粉按一定比例配制）,浇注过程中钢液自动点燃SHS粉料,使其反应生成增强陶瓷相（TiC）。钢液铸渗到反应后的SHS陶瓷层中,使陶瓷增强相均匀地分散到熔融的表层金属中,从而使铸件表面获得TiC/Fe自生复合材料层。表面复合层硬度可达HRC54～59,经900℃×2h退火后,产生大量细小且弥散的二次TiC颗粒。     

固溶处理对ZK60合金组织及性能的影响

对铸态及固溶处理后的ZK 60镁合金的组织、拉伸和锻造性能进行了研究,铸态ZK 60镁合金中β相成连续网状分布,力学性能和变形极限较低,经390℃×16h固溶处理后,β相部分或全部溶入基体中,呈不连续点状分布,抗拉强度和屈服强度较铸态提高14%和28%,伸长率(13%)较铸态提高70%。固溶处理后锻造开裂极限达到85%,较铸态提高20%～25%。结果表明,β相的减少使应力集中和裂纹扩展的可能性减小,有效避免了裂纹的产生和传播,明显提高了ZK 60合金的力学性能和加工性能。     

TiN附着膜的应力-应变关系

利用等离子体辅助化学气相沉积法(PACVD)在60Mn钢基片上沉积2．5μm厚的TiN膜．借助X射线应力分析技术和微拉伸设备，测量该附着膜纵向(加载方向)应力和横向应力及外载应变，进而求其等效应力-等效单轴应变关系，并由此算得它的条件屈服点σ0．1和σ0．2分别为4．2和4．4GPa，加工硬化指数为0．36．用纳米压痕仪测得其硬度为25GPa，弹性模量为420GPa．TiN膜在拉伸过程中发生了塑性变形．     

Mechanism of laser beam welding for SiCp／6063Al composite

The laser beam welding technique was used to process SiC particles/6063A1 alloy matrix composite, the influence of laser power and welding speed on the properties of joint was studied. Decreasing the laser beam power with same welding speed can make the quantity and size of A14C3 decreased, and the interactive mechanism of the reinforcing particles and the matrix in the joint and the causes for joint strength reduction were analyzed.Increasing welding speed properly can improve the distribution of energy and restrain the interfacial reaction in the molten pool, and measures for improving were proposed.