Wear Weight Loss Research Articles

Effects of carbides on abrasive wear properties and failure behaviours of high speed steels with different alloy element content

High speed steels (HSSs) are effective materials applied in aggressive environments where abrasion resistances are required because they have hard carbides and relatively ductile matrix to bind carbides. But there are many kinds of carbides in HSSs, which lead to different effect on wear properties of HSSs. In this paper, three kinds of casting HSSs with VC, M6C or M2C type carbide were prepared respectively through the reasonable design of alloy elements, and then the effects of carbide type on wear behaviours were researched under different abrasive particle size and load using abrasive wear testing machine. The microstructures and failure behaviours of HSSs were analyzed by electron microscopy. The results showed the abrasive particle size and load had obvious effect on wear weight loss of high speed steel (HSS), but the carbide type decided the relative wear resistance of HSS. As the abrasive particle size or load increased, the wear weight loss of any HSS increased obviously. For the fine abrasive wear, the HSS with M6C had higher relative wear resistance than HSS with M2C. But the contrary was the case for the coarse abrasive wear. For any abrasive particle size and load, the HSS with VC had more excellent wear resistance than HSS with M6C or M2C type carbide. The relative wear resistance of HSS with VC was three times higher than that of HSS with M6C or M2C. The excellent wear resistance of HSS with VC was mainly attributed to VC characteristics, such as high hardness and good morphology, which can resist micro-cutting of abrasive particles efficiently.

A Study on Tribological Behavior of AZ31bMg Composite

Objectives: To analyse the wear behavior of AZ31bMg composite under vacuum and atmospheric conditions. Methods/ Statistical Analysis: The wear test is performed in vacuum and atmosphere at elevated temperature by varying the load and sliding distance based on pin- on - disc configuration using oil hardened steel as a counter face. Wear is measured in terms of weight loss using digital balance with an accuracy of 0.0001 g. The Micro structural study is carried out at the worn surface of the specimen. Then the results of vacuum and atmosphere testing are compared. Findings: From the study, it is observed that the wear (weight loss) increases with an increase in load and sliding distance. The same trend is observed when the specimen is tested at elevated temperature; wear rate increased with increase in temperature and it is due to softening of material on contact surfaces. And it is also found that the wear rate of specimen is increased when it is tested in a vacuum. Also, due to partial melted phases covering the pin surface, the weight loss of the specimen decreases with increase in vacuum. Wear debris was found on the surfaces of pin specimen. The Micro structural study is carried out at the worn surface of the pin specimen. The comparison of results indicated that there was a difference in wear behavior in different environments, and AZ31bMg composite could be considered as an excellent material at low temperature and high vacuum condition applications where high strength, less weight and wear resistance are of prime importance. Application/Improvements: The scope of tribology has become increased to embrace numerous areas such as aerospace, computing, micro mechanics and microelectronics. This in turn opens a broad scope for analyzing friction and wear.

Role of SiC ceramic particles on the physical and mechanical properties of Al–4%Cu metal matrix composite fabricated via mechanical alloying

In the present investigation, Al–Cu composites with SiC particulates were fabricated via mechanical alloying process. The aim of this study was to evaluate the effect of milling time (8, 12, 16 and 32 h), particle size (30 nm and 15 µm) and volume fractions (5, 10 and 15 wt.%) of SiC particles on the metallurgical and mechanical properties. Scanning electron microscopy equipped with X-ray diffraction method was used to investigate the microstructural evolution and morphological changes created during mechanical alloying. Microstructural study indicated that SiC particles were well distributed after the mechanical alloying process. A homogenous distribution of the particles was obtained by 15 wt.% of SiC particles in the aluminum matrix. The results revealed that the SiC particle size also affected the distribution and size of the powders in the matrix and it improved as particle size decreased from 15 µm to 30 nm. The study of mechanical properties clearly showed that a reduction in hardness of composite occurs which is attributed to positive effect of reinforcement particles in resistance to the movement of dislocations. Furthermore, it was found that the wear weight loss of Al–Cu/SiC composite decreases monotonically with increasing SiC content and more uniform particle size distribution. The excellent wear rate was primarily attributed to uniform distribution of the SiC particles.

Dry Sliding Wear Behavior of Hafnium-Based Bulk Metallic Glass at Room and Elevated Temperatures

Dry sliding wear behavior of hafnium-based bulk metallic glass was studied at two loads (5 and 15 N) and two temperatures (298 and 673 K) using aluminum oxide (Al2O3) ball as a wear counterpart. At 5 N load, wear reduced by ~71% on increasing the temperature from 298 to 673 K. At a higher load of 15 N, the weight loss reduction was much lower (45%) on increasing the temperature from 298 to 673 K. Decreased wear weight loss on increasing the temperature was attributed to the increased hardness of the Hf-based metallic glass at high temperatures. Micro-hardness of the alloy at 293 K was found to be 636 Hv, which gradually increased to 655 Hv on annealing at 673 K. Improvement in the hardness at elevated temperature is attributed to: (1) free volume annihilation, (2) surface oxide formation and (3) nano-crystallites precipitation. Reduced wear at elevated temperature resulted in smaller volume of debris generation that restricted three-body wear to obtain lower coefficient of friction (COF) (0.25-0.35) compared to COF (0.65-0.75) at room temperature.

Investigation on two-body abrasive wear behavior and mechanism of Fe–3.0 wt% B cast alloy with different chromium content

Effect of chromium content on two-body wear behavior of Fe–3.0wt% B cast alloy was investigated. The wear mechanism with different abrasive, associating with Fe2B toughness, was discussed in the present study. The results indicate, solidification microstructures of the alloy are composed of ferrite, pearlite and eutectic boride, and the heat treated microstructures comprise of martensite and eutectic boride. With chromium content increasing, chromium concentration in boride is 3.82 times higher than that in matrix; microhardness of boride and hardness of the alloy change little, while toughness of boride increases first and then decreases. During two-body wear test, wear weight losses with SiC abrasive are generally higher than those with SiO2 abrasive. With Cr content increasing in the alloy, on condition of SiO2 abrasive, the wear resistance increases first and then decreases, possessing the same trend as the toughness of boride; with SiC abrasive, wear resistance changes in a way similar to that with SiO2 abrasive, except that wear resistance under contact load of 55N increases sharply and then keeps nearly constant. Wear results show that toughness of boride is the main factor to influence wear resistance of Fe–3.0wt% B cast alloy.

The influence of temperature on tribological behaviour of Ni-SiC Electrodeposited coating

In this article, the Electrodeposition of a Ni-SiC composite coating, which is mostly used as wear resistant coating in many applications, such as engine cylinders, combustion engines and casting moulds, was carried out from a sulphamate bath. Both mechanical and ultrasonic stirrers were used simultaneously during the process. Due to the working temperature of coating in the mentioned applications, the wear tests were carried out from 25 to 300 °C by pin-on-disk method and the high temperature tribological behaviour of the coating was investigated. Based on the results obtained from the wear tests, the Ni-SiC coating has low friction coefficient (0.36–0.42) and wear weight loss (0.7–2 mg) values at 25 and 100 °C. But, by increasing the temperature to 200–300 °C, which is near to the working temperature of many applications, the friction coefficient and wear weight loss values significantly increased.

Microstructure and wear resistance of TiCN-reinforced Co matrix coatings on tool steel

TiCN-reinforced Co alloy coatings were successfully fabricated on H13 steel by laser cladding. The microstructure and wear properties at room temperature were investigated. The results showed that the coatings are free of defects with sound metallurgical bonding to H13 substrate. The average microhardness of TiCN-reinforced Co alloy coatings with different contents of TiCN was more than twice to three times that of the H13 steel. The laser clad TiCN-reinforced Co alloy coatings exhibited good friction-reducing and antiwear abilities at room temperature. The composite coating significantly decreased wear weight loss and wear rate as the weight fraction of TiCN increased. TiCN-reinforced Co alloy coatings with smooth worn surface were characterised by mild adhesion wear and slight plastic deformation.

40Cr刀具表面激光熔覆WC/Co50复合涂层的微观组织及其磨损性能

WC/Co50 cladding coating was fabricated on 40Cr cutting tool surface by 6 kW transverse-flows multimode CO2 laser apparatus. The surface morphology, phase composition, microstructure, microhardness and wear behavior of the cladding coating were analyzed by optical microscope(OM), scanning electron microscope(SEM), energy disperse spectroscopy(EDS), X-ray Diffraction(XRD) hardness tester and friction wear testing machine. The results show that the original WC particles were dissolved greatly under the action of high-energy laser beam. The phase of coating is mainly composed of carbides WC, W2C,(Cr, Fe)7C3, W6C and Fe-Cr solid solution. The microstructure of WC/Co50 coating is complex, which consists of the primary dendrites, cellular eutectic, interdendritic eutectic and hard phase particles. The average hardness of the WC/Co50 coating is 1.93 times of the substrate, and the hardness of WC/Co50 cladding coating decreases with the increase of the surface depth. Under the same conditions, the wear weight loss of the composite coating is only 13.3% of the substrate.

40Cr刀具表面激光熔覆WC/Co50复合涂层的微观组织及其磨损性能

WC/Co50 cladding coating was fabricated on 40Cr cutting tool surface by 6 kW transverse-flows multimode CO2 laser apparatus. The surface morphology, phase composition, microstructure, microhardness and wear behavior of the cladding coating were analyzed by optical microscope(OM), scanning electron microscope(SEM), energy disperse spectroscopy(EDS), X-ray Diffraction(XRD) hardness tester and friction wear testing machine. The results show that the original WC particles were dissolved greatly under the action of high-energy laser beam. The phase of coating is mainly composed of carbides WC, W2C,(Cr, Fe)7C3, W6C and Fe-Cr solid solution. The microstructure of WC/Co50 coating is complex, which consists of the primary dendrites, cellular eutectic, interdendritic eutectic and hard phase particles. The average hardness of the WC/Co50 coating is 1.93 times of the substrate, and the hardness of WC/Co50 cladding coating decreases with the increase of the surface depth. Under the same conditions, the wear weight loss of the composite coating is only 13.3% of the substrate.

镁基表面微弧氧化陶瓷膜的摩擦磨损特性

利用微弧氧化技术在AZ91D镁合金表层制备原位生长陶瓷膜，利用SEM、XRD等表征了镁基陶瓷膜，并研究了镁基陶瓷膜的摩擦磨损特性及磨损机理。结果表明，镁基陶瓷膜表面呈典型的微孔叠加多孔结构特征，其主要成分是Mg2SiO4、MgAl2O4、Mg3(PO4)2、MgO，膜层与基体结合紧密，结合力为14~15 N。不同载荷和不同摩擦速度等因素对镁基陶瓷膜的磨损都有很大的影响。随着载荷和滑动速度的增大，陶瓷膜的磨损失重也明显增大。油摩擦的磨耗较小，其磨损机理主要为疲劳磨损，同时也附带磨粒磨损。干摩擦的磨耗较大，其磨损是由磨粒和疲劳磨损共同造成的。 Ceramic film produced on magnesium alloy AZ91D was prepared by micro-arc oxidation. The morphology, phase composition and element distribution of ceramic membrane were tested by SEM, XRD. The growth process and characteristics of the film were analyzed. Then the friction and wear mechanism of coatings on magnesium alloy by micro-arc oxidation method were studied. The results showed that the main components of t coatings on magnesium alloy were Mg2SiO4, MgAl2O4, Mg3(PO4)2 and MgO. The film and the substrate are combined tightly with binding force 14 - 15 N. Factors such as different load and sliding wear speed have great influence on coatings of magnesium alloy by micro-arc oxidation. With the increase of load and sliding speed, the wear weight loss of ceramic coating is also obvious increase. Wear loss is smaller under oil friction condition, and its main wear mechanism is fatigue wear, with less abrasive wear. Wear loss is larger under dry friction condition, and its wear is caused by abrasive grain and fatigue wear together.

Effect of counterpart material on the tribological properties of Zr-based bulk metallic glass under relatively heavy loads

Zr-based bulk metallic glasses (BMGs), especially Zr41Ti14Cu12.5Ni10Be22.5, are widely used as mechanical components due to their simple preparation process and excellent properties. In this study, the tribological properties of Zr41Ti14Cu12.5Ni10Be22.5 pins and different counterpart materials (AISI 5120 steel, AISI 52100 steel and Zr41Ti14Cu12.5Ni10Be22.5 amorphous discs) were investigated using a pin-on-disc tribological apparatus under relatively heavy loads. The structure, thermal stability and wear morphology of the amorphous pins were examined using X-ray diffraction, differential scanning calorimeter and scanning electron microscopy, respectively. Coefficient of friction was in the range from 0.15 to 0.30 and was found to depend on the counterpart material. Wear weight loss of crystalline material disc was lower than that of the pins, whereas the opposite result was obtained when the Zr-based BMG was used as the counterpart material. Also, the wear mechanisms of Zr-based BMG pins included grooves, micro-cracks, peeling-off and vicious flow when it slid against crystallization material. However, rough detached damages and wave-like patterns were found on the BMG pins when amorphous discs were used as the counterpart. Meanwhile, there also existed differences of wear mechanisms between the crystallization material and amorphous discs.

Effect of SiC nanoparticle concentration on the properties of oxide films formed on Ti–10V–2Fe–3Al alloy

Ordinary and composite oxide films were formed on Ti–10V–2Fe–3Al alloy by anodic oxidation process, in the environmentally friendly electrolytes with different concentrations of SiC nanoparticle. The surface morphology and phase compositions of the oxide film were analyzed by field emission scanning electron microscopy and Raman spectrum techniques, respectively. The results showed that the oxide film was covered with rod–like and rimose protuberances, being mainly composed of anatase, rutile, vanadium pentoxide, aluminum oxide and ferric oxide. The thickness was determined by SEM, increasing with a corresponding increase of SiC nanoparticle concentration. The wear resistance and corrosion resistance of the oxide films were evaluated by the ball–on–disc rotating wear tester and potentiodynamic polarization tests at room temperature, respectively. It was found that composite films possessed enhanced wear resistance and corrosion resistance comparing with the ordinary film. However, the wear resistance of oxide film was not better with higher concentration of SiC nanoparticle. The optimal concentrations of nanoparticle aiming at excellent wear resistance and corrosion resistance were 5 and 10 g/L, respectively. The friction coefficient and wear weight loss were 0.18 and 4.2 mg; the corrosion potential and corrosion current density were 0.665 V and 3.65 × 10−10 A/cm2.

Microstructure and wear properties of Fe–6wt.%Cr–0.55wt.%C–Xwt.%Nb laser cladding coating and the mechanism analysis

Ultra-high performance FeCrC laser cladding coatings with different Nb contents were designed. The effect of Nb content on the microstructure and properties of the coating was researched and the corresponding influence mechanism was analyzed. The microstructure of the coating consists of martensite matrix and MC carbide. With Nb content increases form 0wt.% to 0.71wt.%, the martensite matrix is refined and the amount of MC carbide is increased, so the hardness, strength and wear resistance of the coating improve gradually. When the Nb content is 0.71wt.%, all of the properties are the excellent, in which, the hardness is 620HV, the tensile strength and yield strength are 1588MPa and 1344MPa, respectively, the abrasive wear weight loss is 0.15g/h and the COF of adhesive wear is 0.52. The lattice misfit between (110)NbC//(100)α-Fe is 10.3%, which indicates that NbC act as the heterogeneous nucleus of α-Fe is medium effective. With the increase of the Nb content, the precipitation temperature and precipitation amount of MC carbide both increase, when the Nb content is 1.03wt.%, they are 1072°C and 0.97wt.%, respectively.

Effect of vacuum remelting on microstructure and wear resistance of NiCrMoY coatings deposited by supersonic atmospheric plasma spraying

In this study, vacuum remelting was applied on the supersonic atmospheric plasma sprayed NiCrMoY coating with the aim of improving its wear resistance. The microstructure, surface roughness, phase composition, micro-hardness and wear resistance of NiCrMoY coatings before and after vacuum remelting were studied. The results showed that the vacuum remelting eliminated the defects (such as pores and cracks) of plasma sprayed coating and improved its relative density and micro-hardness. Meanwhile, Cr2B and Cr7C3 in the as-sprayed coating transformed to CrB and Cr23C6 after remelting, and some other new phases including Ni3B, Mo2C and NbC were also detected in the remelted coating. The average wear weight loss of remelted coating was about 1.34mg, compared with the 11.88mg of as-sprayed coating indicating that the wear resistance of coating was improved by the vacuum remelting treatment.

Microstructure and mechanical properties of Ni-P-Si3N4 nanowire electroless composite coatings

In this paper, a new Ni-P-Si3N4 nanowire composite coating has been successfully prepared on AZ31 Mg substrate through electroless deposition technique. The effect of Si3N4 nanowire concentration in the plating bath on the surface morphology, hardness and wear behavior of the composite coatings have been investigated. The results show that when the concentrations of Si3N4 nanowire is 1.5g/L, the morphology of composite coating appears the fine nodular structure. Moreover, the Si3N4 nanowire is uniformly dispersed in the coating at the 1.5g/L concentrations of Si3N4 nanowire. But when the concentrations of Si3N4 nanowire in bath over 1.5g/L, the coatings surface morphology become roughness and some pores appear on the coating surface because of the agglomeration of Si3N4 nanowire. As seen from the experiments results, the microhardness of the composite coating were significantly increased to about 790HV200 as plating, the friction coefficient and wear weight loss of the composite coating is both decreased to the 1/6 of conventional Ni-P electroless coating. These improvements have been attributed to the dispersion strengthening effect of Si3N4 nanowire.

Microstructure and Properties of Porous Abradable Alumina Coatings Flame-Sprayed with Semi-molten Particles

High-efficiency gas turbines require high-temperature sealing by use of abradable porous ceramic coatings to increase engine efficiency. In this study, porous Al2O3 coatings were deposited by flame spraying; the coatings were applied in a semi-molten state by controlled melting of the sprayed powder particles. The effects of the degree of melting of the sprayed particles, which depends on spraying conditions, on coating microstructure and porosity were investigated. The degree of melting of the sprayed particles was characterized by use of 3D confocal laser microscopy. The porosity of the coating was estimated by image analysis. The results showed that the degree of melting of alumina particles can be changed from 70 to 30%, and thus coating porosity can be increased from 30% up to over 70%. The standard hardness test yielded no useful data for porous coatings deposited by use of sprayed particles with a degree of melting 60%. Pin-on-disk abrasion tests, performed at room temperature by use of an Inconel 738 (IN738) nickel-based superalloy pin with a spherical tip 5 mm in diameter, were conducted on the porous alumina coating to evaluate its abrasion behavior. It was found that for coatings of hardness 40% the wear weight loss of the IN738 pin was negligible despite the high rate of wear of the coating. It is evident that flame-sprayed porous alumina coatings of high porosity prepared by this approach have potential for use as abradable coatings for gas turbines operating at high temperatures.

Microstructural Characterization and Mechanical Properties of VB2/A390 Composite Alloy

In this work, we make the best use of the vanadium element; a series of Al–V–B alloys and VB 2 /A390 composite alloys were fabricated. For Al–10V–6B alloy, the grain size of VB 2 can be controlled within about 1 µm and is distributed uniformly in the Al matrix. Further, it can be found that VB 2 promises to be a useful reinforcement particle for piston alloy. The addition of VB 2 can improve the mechanical properties of the A390 composite alloys significantly. The results show that with 1% VB 2 addition, A390 composite alloy exhibits the best performance. Compared with the A390 alloy, the coefficient of thermal expansion is 13.2 × 10 −6 K −1 , which decreased by 12.6%; the average Brinell hardness can reach 156.5 HB, wear weight loss decreased by 28.9% and ultimate tensile strength at 25 °C (UTS 25 °C ) can reach 355 MPa, which increased by 36.5%.

Effects of Molybdenum on the Wear Resistance and Corrosion Resistance of Carbidic Austempered Ductile Iron

The effects of molybdenum on the microstructure, wear resistance, and corrosion resistance of carbidic austempered ductile iron were studied. The results show that the microstructures of as-cast samples are mainly composed of nodular graphite, pearlite and carbides, and the nodularization grade is 2–3 and graphite size is 6–7 magnitude in all samples. With the increase of Mo content, the amount of nodular graphite decreases, but the pearlite and carbides increase. The microstructures of all heat-treated samples mainly consist of nodular graphite, acicular ferrite, retained austenite, and a certain number of carbides. As the molybdenum content increases, the quantity of retained austenite and carbides increases, the acicular ferrite becomes finer, and the wear resistance and corrosion resistance increased. When the concentration of molybdenum reaches 0.570 wt%, the average wear weight loss decreased to 0.218 mg/m, the corrosion potential reached to −0.5626 V, and the corrosion current density decreased to 6.361 × 10−8 A/cm2.

Influence of Particle Size of Wheat Powder on Roller Wear Properties

Wheat milling process involves multiple grinding procedures, the wheat powder particles size in different grinding procedure are difference. In order to study the influence of particle size of wheat powder on roller wear performance in different grinding procedure, abrasion experiments were carried out by MLS-225 three-body abrasive wear tester, while different sizes were chosen as abrasive, alloy white iron which frequently used as roller metal materials was chosen as wear sample, wear weight loss and surface microstructure were chosen as the main evaluation indicators. The results showed that the weight loss of samples were showed a linear relationship with wheat the size of wheat powder. The main wear behavior was mainly mechanical polishing while particle sizes was smaller one. For the larger size, wear was made by multiple plastic deformation and low cycle fatigue wear mechanism.

Effect of Rotational Sliding Velocity on Micro Tribological Behaviors of Cu50Zr50 Amorphous Alloy Foils

In this study, the micro tribological behavior of Cu50Zr50 amorphous alloy foils was investigated experimentally at room temperature by pin-on-disc tribological tests. It is found that the friction coefficients are mainly located between 0.15 and 0.45, and increase with the rotational sliding velocity. With the increase of rotational sliding velocity, the wear weight loss also increases. At lower rotational sliding velocity, the wear mechanism tends to a combination action of continuous wear and surface flow. At higher rotational sliding velocity, the wear mechanism tends to a continuous wear. The reported results provide a basis understanding of the tribological behavior of Cu50Zr50 amorphous alloys in micro scale.