Wear resistance of surface-modified TiNbSn alloy

Journal of Materials Science - The wear resistance of TiNbSn alloy surfaces treated by plasma nitriding, TiN sputtering, and anodic oxidation was investigated with the goal of suppressing the...     

Wear resistance of titanium alloys after thermodiffusional chromosiliciding

The article describes a new chemicothermal treatment for titanium alloys, which consists in thermodiffusional chromosiliciding in vacuum. Results of wear tests on titanium alloys subjected to this treatment and data on the effect of the treatment conditions on the wear resistance of these alloys are presented.     

Wear resistance of plasma coatings on mild steel

Mild steel was coated by different materials using plasma spray technique. Materials used as coatings are Ni-5% Al and WC-17% Co. The thickness of the coatings varied between 0.05 to 1.5 mm. The porosity of different coatings decreased with increase in thickness of the coat. The roughness of coating material decreased after wear testing. Microstrueture study has been conducted for coatings of different materials before and after wear testing. Wear tests have been conducted under different aqueous environments at room temperature. The wear resistance of Ni-5% Al coating was improved by heat treatment. X-ray diffractometry showed the presence of NiO in the outer layer of the Ni-5% Al coating. The thickness of the coating, type of coating, heat treatment conditions, and the environment of testing proved to affect the rate of wear resistance.     

Wear resistance of blade materials subjected to stress corrosion

We study the influence of preliminarily made notches on the fatigue resistance of 12Kh13 steel specimens and the influence of the magnitude of constant and variable loading and the time of holding in corrosive media (in a saturated and deaerated solution of sodium chloride) on the development of pit corrosion. It is shown that the effect of hardening observed after preliminary stress corrosion for 240 h affects the durability of the material in air. At the same time, in corrosive media, this effect is not observed if the time of preliminary holding is greater than 24 h. We also establish the dependences of the diameters of corrosion pits at the bottom of the notch on the loading mode and on the time of holding in the medium.Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Moscow Institute of Power Engineering, Moscow. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 31, No. 3, pp. 106–110, May–June, 1995.     

热锻模具钢的耐磨性及磨损机理研究

采用销盘式高温摩擦磨损实验机,针对一种新型铸钢、H13和H21钢在25-400℃下进行磨损试验,对比研究各种钢的耐磨性,并探讨了磨损机制.研究表明:室温下H21钢由于具有较多的未溶碳化物,比H13钢和铸钢具有高的耐磨性;在200-300℃下铸钢和H13钢随载荷的增加一直具有较低的磨损率和增长率,而H21钢当载荷达到200 N时磨损率忽然升高;在400℃下铸钢具有持续低的磨损率,明显低于H21和H13钢.可见,新型铸钢具有比常用热锻模具钢显著高的高温耐磨性.     

Wear resistance of nano-polycrystalline diamond with various hexagonal diamond contents

Wear resistance of nano-polycrystalline diamond (NPD) rods containing various amounts of hexagonal diamond has been tested with a new method for practical evaluation of the wear-resistance rate of superhard ceramics, in addition to the measurements of their Knoop hardness. The wear resistance of NPD has been found to increase with increasing synthesis temperature and accordingly decreasing proportion of hexagonal diamond. A slight increase in Knoop hardness with the synthesis temperature also has been observed for these samples, consistent with the results of the wear-resistance measurements. These results suggest that the presence of hexagonal diamond would not yield any observable increase in both hardness and wear resistance of NPD, contradictory to a recent prediction suggesting that hexagonal diamond is harder than cubic diamond. It is also demonstrated that NPD is superior to single crystal diamond in terms of relatively homogeneous wearing without any significant chipping/cracking.     

Wear resistance of plasma coatings for a constant work of friction

We analyze the wear resistance of plasma coatings for a constant work of friction. The dependences of the wear resistance of the coatings are obtained for a broad range of loading conditions. It is shown that the minimum sensitivity to loading conditions is exhibited by the molybdenum coatings. It is also established that the wear resistance of the coatings decreases as the amplitude of displacements increases and the cyclic frequency of the tests decreases due to the intensification of fatigue processes on the surfaces. The comparative characteristics of coatings are presented. __________ Translated from Problemy Prochnosti, No. 5, pp. 94–100, September–October, 2007.     

Wear resistance and wear mechanisms in polymer + metal composites

We have investigated composites containing metallic micro-size and nano-sized particles as the 10 wt% dispersed phase. Branched low density polyethylene (LDPE) was the matrix. Microsized metals were Al, Ag and Ni; nanosized metals were Al and Ag. Several mechanisms of wear are observed in function of the kind and size of metal used: deformation, delamination, abrasion, adhesion and rolls formation. The presence of Ag particles increases the wear rate as compared to neat LDPE. The presence of Al particles lowers the wear of LDPE significantly; nanoparticles are more effective than microparticles.     

铸铁表面激光熔敷镍基合金涂层的耐磨性研究

为了提高铸铁的耐磨性，以35％WC和不含WC的镍基合金粉末为原料对铸铁表面进行激光熔敷处理，利用XRD、SEM、TEM等技术分析了涂层的成分及显微组织结构，并测试了涂层的耐磨性和硬度．结果表明：激光处理后表面迅速熔化和冷却，组织由珠光体 片状石墨组织转化为不同粗细的针状马氏体与残余奥氏体组织；熔敷层的耐磨性和硬度明显提高，且添加35％WC硬质颗粒的熔敷层硬度最高值不在最表层，而在距表面约0．2mm处；合金涂层在磨损机制下表现为犁沟切削、微切削以及硬相质点的剥落，不同基体划痕形式不同。     

Wear resistance of TiN coatings implanted with Al and N ions

Titanium nitride (TiN) coatings were prepared on HS 6-5-2 high-speed steel cutting inserts and next implanted either with Al ions (fluence 2×10¹⁷ ions/cm²) or with Al and N ions (fluence (1+1)×10¹⁷ ions/cm²) on the rake face. Microhardness and friction coefficient of the implanted surfaces were examined. A noticeable increase of microhardness in Al implanted inserts has been observed.The elemental composition and structural properties of the surface layer were examined by glow discharge optical emission spectroscopy (GDOES) and gliding angle X-ray diffraction (XRD).The tests of turning of 40 H constructional steel with the cutting inserts have shown an improvement in the implanted inserts, especially marked in those implanted with Al+N.     

剑麻纤维/酚醛树脂原位复合材料耐磨性能研究

为了探讨剑麻纤维对复合材料耐磨性能的影响,采用聚合填充工艺,通过模压成型方式制成剑麻纤维/酚醛树脂(SF/PF)原位复合材料.考察了SF的表面处理方式、用量、长度以及同玻璃纤维(GF)混杂增强与复合材料耐磨性能的关系;用扫描电镜(SEM)对材料磨损的表面形态结构进行了研究.结果表明,SF的用量和长度对材料的耐磨性能有一定影响,合适的用量和长度是得到高耐磨性能复合材料的必要条件,GF与SF混杂后材料的耐磨损性能随着SF用量的增加而增加;SEM揭示了复合材料相应的磨损机理.SF表面处理后复合材料的耐磨性能得到了显著提高.     

Wear resistance of Fe-based amorphous coatings prepared by AC-HVAF and HVOF

Fe₆₃Cr₈Mo_3.5Ni₅P₁₀B₄C₄Si_2.5 amorphous coatings have been prepared by the activated combustion high velocity air fuel (AC-HVAF) and high velocity oxygen fuel (HVOF) processes. The microstructure and wear resistance of the amorphous coatings are comparatively studied. The wear volume loss of the AC-HVAF coating is approximately seven times less than that of the HVOF coating, indicating that the AC-HVAF coating exhibits better wear resistance. Detailed analysis on the worn surface indicates that the enhanced wear resistance of the AC-HVAF coating is mainly attributed to the formation of a more stable oxide tribolayer and smoother worn surface, which result from the dense and complete amorphous microstructure of the AC-HVAF coating. The wear mechanism of the amorphous coatings is dominated by oxidation wear.