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1.
Selective laser melting (SLM) is one type of additive manufacturing which produces metal parts by powder bed fusion. Since the materials undergo repeated and sharp heating/cooling cycles, the SLMed parts have unique microstructures. The relations among SLM processing parameters, resultant microstructures, and mechanical properties have been investigated by many researchers. However, the wear performance of SLMed materials under various contact conditions has not been carried out until recently. This paper is a presentation of previous and recent research related to wear performance. This is a crucial aspect if SLM is to be expanded to produce friction pairs. Wear rates and mechanisms of the SLMed materials under dry, boundary lubrication, cavitation erosion, and corrosion conditions are discussed and compared with conventionally processed (CP) materials. SLMed materials benefit from fine grains and high hardness, which have higher wear resistance than CP materials. Moreover, a unique tribo-layer on the surface of the SLMed part is found to protect the bulk material under boundary lubrication conditions. An optimized combination of processing parameters increases part density, which further improves the wear resistance. Future work includes studying the influence of pores on the deforming and lubricating behaviors from dry conditions to different lubrication regimes. The final target is to actively control the processing parameters to obtain desirable material properties for improving wear performance. 相似文献
2.
Wei Fuming Huang Zheng Zhu Yanian Zhou Jun Yu Heying Xu Ting Liu Feng Yao Yong 《上海大学学报(英文版)》1998,2(2):148-155
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为了进一步研究化学镀镍磷复合镀层的性能,在研究了镍磷化学复合镀新配方的基础上,在A3钢片表面分别制备了纳米和微米复合材料镀层N i-P-MgO(CuO).用称重法测定厚度;通过10%NaC l溶液测定其耐腐蚀性;GB5935 86标准贴滤纸法测镀层的孔隙率;MH-3硬度仪测定其硬度.结果表明:在最佳施镀条件下,可得到耐磨性、硬度强于A3钢片、N i-P镀层和N i-P-MgO(CuO)纳米复合镀层的微米复合化学镀层,和光亮致密耐腐蚀性强于A3钢片、和N i-P-MgO(CuO)微米复合镀层,与N i-P镀层相当的N i-P-MgO(CuO)纳米复合镀层. 相似文献
4.
采用HL-5000型横流CO2激光加工机在TC4钛合金表面激光熔覆TiC+Ti和TiC+Ti+F102复合涂层。通过SEM、EDAX、XRD、HXD-1000TMC型显微硬度计,HT-600型高温摩擦磨损试验机,分析了熔覆层的显微组织、成分、物相,测试了激光熔覆层的显微硬度和滑动摩擦磨损性能。结果表明,激光熔覆制备的TiC复合涂层与基体呈冶金结合,在TiC+Ti激光熔覆层中,熔覆层的组织是在Ti基体上分布着TiC树枝晶;在TiC+Ti+F102激光熔覆层中,TiC颗粒发生了部分溶解,熔覆层的组织是在Ti基和γ-Ni基的基体上分布着细小的TiC颗粒和TiC树枝晶。TiC+Ti激光熔覆层的硬度约为700 HV0.1,TiC+Ti+F102激光熔覆层的硬度约为800 HV0.1,两种复合涂层耐磨性均比TC4钛合金显著提高。 相似文献
5.
利用反应等离子熔覆技术、以Fe-Cr-C-W-Ni合金粉末为原料,在Q235钢表面制得了Cr7C3高铬铁基金属陶瓷增强耐磨复合涂层。利用SEM、EDS和X射线衍射分析了涂层的显微组织,在室温干滑动磨损试验条件下测试了涂层的耐磨性。结果表明:反应等离子熔覆Cr7C3高铬铁基金属陶瓷增强耐磨复合涂层硬度高、组织均匀、与基材之间为完全冶金结合;涂层在室温干滑动磨损试验条件下表现出优异的耐磨性,涂层磨损的质量损失随载荷增加十分缓慢,涂层具有优异的载荷特性。 相似文献
6.
研究了不同养护制度对超高性能纤维增强水泥基复合材料(UHPFRCC)微观结构和宏观性能的影响,并揭示了用不同的养护制度制备性能符合要求的超高性能纤维增强水泥基复合材料的可能性.制备了一种基准的UHPFRCC,研究了3种养护制度下UHPFRCC的力学性能及短期耐久性能.此外,通过结合运用电子扫描电镜(SEM)和压汞法(MIP),测试了3种养护制度下UHPFRCC的微观结果.研究结果揭示了不同的养护制度对UHPFRCC微观结构的影响以及微观结构对材料宏观性能的影响机制.热养护和蒸汽养护3d与标准养护90 d的UHPFRCC具有相近的力学性能和耐久性.但是,热养护的UHPFRCC具有相对较差的抗氯离子渗透性能. 相似文献
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8.
晁拥军 《温州职业技术学院学报》2001,1(2):38-39
本通过对渗硼层显微组织和性能的分析及渗硼后试件耐磨性的试验，研究了自保护膏剂渗硼及复合热处理工艺对工件耐磨性的影响。结论是：自保护膏剂渗硼后，进行不同温度复合热处理，表面高硬度的硼化组织与不同种类的基体组织结合，所表现出的耐磨性是不同的。 相似文献
9.
Junaidi Syarif Agung Iswadi Mariyam Jameelah Ghazali Zainuddin Sajuri Mohd Zaidi Omar 《浙江大学学报(A卷英文版)》2013,14(12):906-914
The effect of solute Cu and Cu precipitates on the wear behavior of ferritic iron under an unlubricated condition was investigated. The specific wear rate of Cu-containing steel abruptly decreased up to 50 N of load, and then gradually decreased with further increased load. The specific wear rate of the as-quenched specimen, in which Cu was in a solid solution, was the lowest among all the specimens at low loads, and all specimens had almost the same specific wear rate at high loads. Subsurface observation showed that the hardness increments of all specimens decreased with increased depth below the worn surface. The as-quenched specimen had a relatively large depth of deformed region than the other specimens even though the increments in hardness were almost the same for all specimens at low loads. With the same hardness at an unworn state, the as-quenched and over-aged specimens exhibited a substantial increase in hardness and large deformed regions below the worn surfaces. This finding indicated that the enhancement in plastic deformation and work hardening led to the decrease in the specific wear rate of the as-quenched specimen at low loads and the improvement in the wear resistance of all specimens at high loads. 相似文献
10.
通过超音速火焰喷涂工艺在Cr12模具钢表面上喷涂制备了WC-x Co-3Cr(x=8,10,12,14)涂层,并采用金相显微镜、扫描电镜、显微硬度仪和摩擦磨损试验机表征分析涂层的微观结构、显微硬度、耐磨损性能和耐腐蚀性,考察了不同Co含量对涂层组织和性能的影响。结果表明,Cr12模具钢超音速火焰喷涂后表面的耐磨损性能比喷涂前的基体耐磨损性能有较大的提高;表面硬度在不同程度上都得到提高,界面结合良好,其中WC-10Co-3Cr涂层的组织致密性最好、显微硬度最高、耐磨损及耐腐蚀性能最好。 相似文献
11.
《浙江大学学报(A卷英文版)》2021,(2)
In this study, the effects of five different ionic and nonionic surfactants on the physical properties and microstructures of a metakaolin-based geopolymer(MKG) were investigated. It is the first comprehensive comparative study of the effects of sodium lauryl sulfonate(SLS), alkyl polyglycoside(APG), benzalkonium chloride(BAC), sucrose fatty acid esters(SE), and stearic acid(STA) on MKG. Viscosity, densities, apparent water absorption, and compressive strength were measured, and pore structures, micro-defects, and gels observed through scanning electron microscopy(SEM) and mercury intrusion porosimetry(MIP). In the MKG slurry, a high affinity of surfactants to liquid-air interfaces increased viscosity and promoted the generation of bubbles. Based on both the ionic types and molecular configurations of the surfactants, stronger adsorption of a surfactant on the surface of the metakaolin resulted in better dispersion of metakaolin particles and a denser microstructure of the MKG. The surfactants with weaker adsorption(SLS and APG) caused higher porosity, a larger pore size, and more micro-defects, while those with stronger adsorption(BAC, SE, and STA) led to relatively lower porosity and denser microstructures. Density, water absorption, and compressive strength were closely related to the total intrusion porosity of the MKG. The mechanisms underlying surfactant adsorption to the surface of metakaolin are proposed. 相似文献
12.
采用金相显微镜和透射电镜观察了三个600MPa级冷轧双相钢的组织特征并分析了组织与性能的关系。试样组织均由铁素体和马氏体岛组成。1#、2#、3#试样的马氏体岛体积百分比分别为:13.87%、10.48%、6.49%,对应的抗拉强度分别为723MPa、654MPa、594MPa,表明随着马氏体体积百分比增加双相钢的抗拉强度逐渐上升。2#试样中发生碳化物分解的岛数量最多,屈服强度最低,推测马氏体分解,产生体积收缩,铁素体中位错发生恢复和松弛,是降低屈服强度的重要原因。 相似文献
13.
以 L i2 CO3-Si O2 为液相掺杂剂 ,采用一次烧成工艺 ,制备出半导体的 Sr Ti O3基压敏与介电性的双功能陶瓷 .通过电性能与微观结构分析 ,研究了液相掺杂浓度、L i/Si比值及烧结温度对材料性能的影响 .结果表明 ,以 6× 10 - 3mol/L的 Li2 CO3 Si O2 为液相掺杂剂 ,L i/Si=3 /2 ,温度为 13 80℃时 ,在石墨和氮气形成的还原性气氛中烧成的 Sr Ti O3基材料可获得优异的压敏与介电双功能特性 相似文献
14.
陶瓷的热压烧结 总被引：3，自引：1，他引：3
王月花 《周口师范学院学报》2004,21(2):44-46
采用由自蔓延高温还原技术合成的TiB2陶瓷粉料,在不同烧结温度下热压制取TiB2陶瓷材料,对该材料的力学性能和微观结构特征进行研究.结果表明:随着烧结温度的增加,TiB2陶瓷材料的相对密度、硬度和抗弯强度都呈现先快后慢的增加趋势,导电性能增强. 相似文献
15.
Researchershavebecomeincreasinglyinterestedinironaluminideintermetallics (includingFe3AlandFeAl)since 1970sinviewofthecombinationoflowcost,lowerdensity ,remarkableresistancetoerosion ,sulfidizingandoxidizingathightemperature .However ,industrialap plicationofthesealloyshasbeenverylimitedduetotheirpoorductilityandfracturetoughnessatroomtemperatureaswellastheirdifficultyinshaping[1] .Somestudieshaveindicatedthatcoatingstructuralmaterialswithironaluminidesbyusingthermalsprayingwillnotonlysolveth… 相似文献
16.
利用废陶瓷辊棒作为主要原料采用高温煅烧法制备堇青石陶瓷材料,研究了烧成工艺对堇青石材料的晶相、显微结构和性能的影响。利用X射线衍射仪表征试样的晶相结构;利用扫描电子显微镜观察试样的显微结构;利用排水法测试试样的显气孔率和体积密度;通过万能试验机检测试样的抗弯强度。研究结果表明:试样经煅烧后形成堇青石陶瓷材料,主晶相为堇青石相,次晶相为镁铝尖晶石相。堇青石呈粒状分布,试样中具有一定量的玻璃相,均匀地分布着微米级的微孔。随着煅烧温度和保温时间的增加,显气孔率先减小后增大,体积密度先增大后减小,抗弯强度先增大后减小,最佳烧结工艺为煅烧温度1 350℃保温时间3h时,显气孔率最小为21 %,体积密度为1.96 g/cm3,抗弯强度最大为58 MPa。 相似文献
17.
聚苯胺作为一种新型的金属腐蚀防护材料,成为当前的一个研究热点.分别用原位聚合法和恒电位法在不锈钢表面合成导电聚苯胺,采用阳极极化曲线和电化学阻抗谱测试等方法研究它对不锈钢在3.5%NaCl溶液中的抗腐蚀能力,并用红外光谱和X射线衍射分析其结构.结果表明,覆有聚苯胺的不锈钢在3.5%NaCl溶液中的自腐蚀电位和极化电阻都明显增大,说明聚苯胺膜的存在明显减慢了不锈钢在氯化钠溶液中的腐蚀速度. 相似文献
18.
选择含氮节镍型QN2109Mo奥氏体不锈钢作为研究对象,采用XRD、TEM、SEM、EDS、摩擦磨损试验机和电化学工作站等检测手段,研究QN2109Mo不锈钢的组织结构、摩擦磨损性能以及耐腐蚀性能,并与316L不锈钢进行对比。实验结果表明:N原子主要以间隙固溶形式存在于QN2109Mo不锈钢中,对QN2109Mo不锈钢组织起到了细化作用,提高了QN2109Mo 不锈钢的硬度。在干摩擦状态下,QN2109Mo不锈钢的耐磨损性能优于316L不锈钢,其磨损机理为氧化磨损和磨粒磨损共同作用。在w(NaCl)为3.5%的溶液中,QN2109Mo不锈钢表现出比316L不锈钢更低的自腐蚀电流密度和更高的点蚀电位,具有更优异的耐NaCl 溶液腐蚀性能。 相似文献
19.
刘雪华林伟明商川杨斯盛 《福建工程学院学报》2020,(3):241-245
结合溶胶-凝胶法和化学镀方法,于镁合金基材表面成功制备了均匀的复合Ni-P-SiO_2/TiO_2/Al_2O_3镀层,采用扫描电镜(SEM)、光学显微镜(OM)、摩擦磨损试验及电化学方法,对比研究了Mg基材、基础Ni-P镀层与3种复合镀层的显微组织结构、耐磨性及耐腐蚀性。结果表明,加入3种溶胶所制备的复合镀层较Mg基材大幅度提高耐磨性和耐腐蚀性;3种复合镀层较Ni-P镀层具有更加均匀、致密的显微形貌,减少了直接加入纳米粉末的团聚,同时耐磨和耐蚀性改善。其中Ni-P-SiO_2复合镀层具有较高的显微硬度(HV513)和最低的摩擦系数(0.34),最高的腐蚀电位(-1.18V)及较小的腐蚀电流密度(9.5×10~(-3)mA·cm~(-2))。综合制备最佳工艺,并考虑节能减排因素,Ni-P-SiO_2复合镀层可作为性能优良的Mg合金耐磨、耐腐蚀镀层使用,于实际工业生产大有裨益。 相似文献
20.
Engineering properties of sintered waste sludge as lightweight aggregate in a densified concrete mixture 总被引：1，自引：0，他引：1
The global trend towards carbon reduction,energy conservation,and sustainable use of resources has led to an increased focus on the use of waste sludge in construction.We used waste sludge from a reservoir to produce high-strength sintered lightweight aggregate,and then used the densified mixture design algorithm to create high-performance concrete from the sintered aggregate with only small amounts of mixing water and cement.Ultrasonic,electrical resistance and concrete strength efficiency tests were perfo... 相似文献