Average Value Of Friction Coefficient Research Articles

Investigation of the effect of current density and ZrO2 bath concentration on electrodeposited Ni-P/ZrO2 composite coatings

In this study, Ni-P/ZrO2 nanocomposite coatings were deposited on St-37 steel substrates using the electroplating method with varying ZrO2 concentrations and current densities. To investigate the effects of electrolyte components and current density on coating properties, analyses were performed regarding microhardness, wear performance, and surface morphology. As a result of the analyses, it is observed that different bath concentrations and current densities significantly affect properties such as morphology, hardness, and wear performance. It is seen that the surface morphologies of the obtained coatings are generally smooth, but it is understood from the optical images that the surfaces of all nanocomposite coatings are rougher. While adding ZrO2 nanoparticles to the main matrix increases microhardness by approximately 40% compared to pure nickel, a similar but higher hardness value was obtained with the increase in current density. When examined in terms of wear performance, an average friction coefficient value of 3.15 times higher than that of pure nickel nanocomposite coatings was obtained.

Friction wear resistance of 42CrMo4 surface layer after low-pressure ferritic nitrocarburising (FNC)

The work aimed to assess the performance properties of layers produced using the low-pressure ferritic nitrocarburising technology, in particular wear resistance under friction conditions. The assessment has been made in relation to analogous elements subjected only to heat treatment (hardening with tempering).The material for the tests consisted of two groups of friction pairs (5 friction pairs in each group) made of 42CrMo4 steel. The 42CrMo4 steel has been heat-treated (hardening at 880C in oil, tempering at 570C for 2 hours). Half of the samples have been subjected to low-pressure ferritic nitrocarburising at 560C for 6 hours. The friction test has been conducted according to the PN-75/M-04308 standard for 2 minutes at a load of 445 N.The test results showed that the elements after ferritic nitrocarburising had almost twice the surface hardness (662 HV1) than the control group (339 HV1). The average weight wear of the heat-treated and ferritic nitrocarburised elements has been 0.011 g, with an average wear in the control group of 1.022 g. The average friction coefficient in the heat-treated and ferritic nitrocarburised friction pairs was 0.188, while in the heat-treated only pairs, it was 0.358. The Man-Whitney U test has shown that the differences between the average weight wear and the average friction coefficient values are significant (p<0.05).The paper investigates the effect of low-pressure ferritic nitrocarburising technology on the surface layer of steel materials.Low-pressure ferritic nitrocarburising technology shows the potential for practical applications in industrial reality at a level at least equivalent to those currently used worldwide.It is the first known publication on the effect of low-pressure ferritic nitrocarburising technology on the performance properties of the surface layer of elements improved by this method.

Effect of radiation sensitizer on the friction, mechanical and thermal degradation properties of electron beam cured FKM-PTFE composite

Friction coefficient behaviour of electron beam cured vinylidene fluoride-hexafluoropropylene copolymer fluorocarbon rubber (FKM) with 30% loading of polytetrafluoroethylene micro-powder (PTFEMP) irradiated at 250 kGy dose were studied by using a pin-on-disk tribometer for a total testing distance of 360 m in dry conditions at a sliding speed and applied normal load (FN) of 0.05 m/s and 1 N respectively. The same tests were done on the 70/30 blend added with radiation sensitizers n,n-1,3 phenylene bismaleimide (HVA2), trimethylol propane triacrylate (TMPTA) and tripropylene glycol diacrylate (TPGDA). The average friction coefficient (μ) value of all the composites with sensitizer decreased with the TMPTA system recording the lowest μ value which reduced by almost half compared to the pure composite due to better crosslinking density of the vulcanizate. Analysis of the friction coefficient curve behaviour showed an initial low value but displaying an increasing trend versus distance in the TMPTA and TPGDA composites while HVA2 composite recorded an initial high value but showed a reducing trend versus distance. HVA2 composite also recorded the best tensile strength results due to its influence in promoting better synergistic effect and miscibility of PTFEMP filler in FKM matrix.

Investigation of high-temperature wear behavior of Ni-Mo alloyed hardfacing coatings applied on hot strip mill vertical rolls by submerged arc welding

In this study, hot strip mill vertical rolls made of AISI 4140 steel, commonly used in the iron and steel industry's hot rolling section, were coated with ER430 and E430+EC410NiMo using the submerged arc welding (SAW) method. The coatings were characterized through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), microhardness, and wear testing (room 24 °C, 300 °C, and 600 °C). XRD analysis showed that in the ER430 sample, the dominant phase was α-ferrite phase and a small amount of γ (austenite) phase observed, while in the ER 430+EC410NiMo sample, the α-ferrite phase was the dominant phase, but the γ (austenite) phase in the structure was more severe and additionally M6C carbide phase was formed. Coating thicknesses and microhardness values of ER430 and ER430+EC410NiMo coatings were measured as 1.5 mm and 3.75 mm thicknesses, and 533±42 HV0.1 and 473±35 HV0.1 respectively. The increase in hardness on the surface of coated specimens resulted in higher wear resistance compared to the uncoated specimens under all conditions. Regarding average friction coefficient values, coated specimens generally exhibited lower values, although in some cases, the average friction coefficient was higher. In the wear tests, the lowest wear volume losses occurred in the tests conducted at 300°C, while the highest wear volume losses were observed in the tests at 600°C. Upon evaluating the wear mechanisms, it was determined that adhesive and oxidative wear mechanisms were generally dominant in the coated specimens. At higher temperatures, oxidative wear mechanisms became more prominent. ER430+EC410NiMo coatings exhibited better wear resistance compared to ER430, which can be attributed to the toughness effect of γ (austenite) and M6C phases in these coatings. Consequently, it was concluded that applying powder deposition coatings onto hot strip mill vertical rolls made of AISI 4140 steel could enhance their wear resistance, thereby increasing productivity in manufacturing processes.

A review of Influence of MoS2 on the tribological characteristics of diamond-like carbon coatings

Diamond-like carbon (DLC) coatings are increasingly used on machine parts due to their excellent friction and wear resistance. Therefore, it is important to formulate lubricants that can work effectively with these coatings. To do this, it is necessary to know how the various surface-reactive additives generally used in lubricants behave with DLCs. Tribological contacts (friction and wear) with solid lubricant coatings generally result in the transfer of a thin layer of material from the surface of the coating to the mating surface, commonly referred to as a transfer film or tribofilm. The wear surfaces may have different chemistry, microstructure and crystallographic texture than that of the main coating due to chemical reactions of the surface with the surrounding environment This article deals with the behavior of molybdenum dichalcogenide as a surface coating or as a filler in lubricating composites. The inherent lubricating lamellar structure of pure MoS is described, along with a brief summary of its wear and failure modes. Tribological performance of the DLC coatings, in combination with various base oils and lubricant additives, is analyzed by comparing their average friction and wear coefficient values, which have been calculated from published experimental data.

STAND FOR TRIBOLOGICAL STUDIES OF HIP JOINT ENDOPROSTHESIS WITH THE POSSIBILITY OF CHANGING ACETABULUM ANTEVERSION ANGLE AND HEAD ANTI TORSION ANGLE

The article presents the construction of a hip joint movement simulator intended for friction and wear studies of hip joint endoprostheses. The simulator's design enables the fixing of hip endoprosthesis components in accordance with the anatomical structure of the human hip joint. The endoprosthesis head is mounted on a special base in the lower position with a neck-shaft angle of 135°, while the acetabular cup of the endoprosthesis is mounted in the upper part of the mounting head with an inclination angle of 45°. The production of three heads (responsible for the anteversion angle of the acetabulum) and three special bases (responsible for the anti torsion angle of the head) with different fixing angles of the components of the hip joint endoprosthesis made it possible to carry out tribological tests with nine variants of alignment settings. The hip joint endoprosthesis tester is designed to simulate the following movements: flexion and extension, as well as loads occurring in the human hip joint while walking. Thanks to the use of control in the form of electronic cams, the simulator makes it possible to recreate the variable value of the force loading the friction pair as a function of the human walking cycle. The subject of friction and wear studies were hip joint endoprostheses with a head diameter of 44 mm, made of high-carbon Co28Cr6Mo alloy. For each of the nine variants of endoprosthesis component alignment settings, average friction coefficient values were calculated based on the recorded values of the friction torque. The results of the friction and wear studies employing the simulator confirm that the mutual angle alignment setting of the head and the cup has an impact on the value of the frictional resistance occurring in the tribological pair.

Microstructures and properties of AlCrFeNiMnx high-entropy alloy coatings fabricated by laser cladding on a copper substrate

In this study, AlCrFeNiMn x high-entropy alloy coatings (x=0, 0.5, and 1) were successfully prepared on a copper substrate by laser cladding. The influence of Mn addition was investigated on the phase constituent, microstructure, and mechanical properties of the HEA coatings. Due to the high-entropy effect, the AlCrFeNiMn x HEA coatings comprised only simple BCC and FCC structure phases. Moreover, the addition of Mn elements inhibited the formation of FCC phases due to the variation of ΔG mix , ΔH mix , δ, ∆x and VEC value. The addition of Mn leads to solute effect, so the grains were significantly refined with an increase in Mn content. When the Mn content was 0.5, good comprehensive mechanical properties were obtained with an average Vickers hardness of 625 HV, average friction coefficient value of 0.42, and a mass loss of 1.02 mg. • AlCrFeNiMn x HEA coatings are prepared on a copper substrate by laser cladding. • The addition of Mn inhibited the formation of FCC phase of the AlCrFeNiMn x HEAs. • The addition of Mn can significantly refine grains of the AlCrFeNiMn x HEAs. • The addition of Mn can improve the mechanical properties of the AlCrFeNiMn x HEAs.

Experimental investigation on the friction characteristics of hazelnut powder reinforced brake pad

After the realization that asbestos fiber is harmful to human health, efforts to produce organic and environmentally friendly brake pads have increased. In this study, an environmentally friendly brake pad (NUS sample) was produced with the addition of 3.5% hazelnut shell powder. Hardness and density measurements of the brake pad sample were made. Chase type device was used for the wear and friction tests. The experiments were done according to the SAE J661 standard. The average friction coefficient value obtained as a result of the experiments was found to be 0.435 µ. Bu değer standartlara uygundur ve “FF” sınıfı aralığındadır. This value complies with the standards and is in the "FF" class range.

Study of wear and corrosion behavior of cathodic plasma electrolytic deposition of zirconia– hydroxyapatite on titanium and 316L stainless steel in Ringer’s solution

Abstract The wear resistance and corrosion behavior of titanium and 316L stainless steel were studied after depositing a composite coating of zirconia and hydroxyapatite using the cathodic plasma electrolytic deposition technique. No sign of adhesive wear was observed on coated samples due to the unique surface morphology of the treated samples, after a pin on disk wear test in Ringer’s solution. The average values of friction coefficient for treated titanium and steel samples were observed to be 0.2 which exhibited a decrease of about 4 fold for titanium and 7 fold for steel with respect to the substrates. As a result of potentiostatic cyclic tests in Ringer’s solution the corrosion current density of coated steel (2.47 × 10–10 A cm–2) was found to be much lower than for the steel substrate (1.87 × 10–7 A cm–2), treated and untreated Ti (6.60 × 10–6, 4.17 × 10–7 A cm–2), indicated the increase in corrosion resistance of steel and decrease of it for titanium after coating.

Effects of NbC content on microstructural evolution and mechanical properties of laser cladded Fe50Mn30Co10Cr10-xNbC composite coatings

In this paper, NbC reinforced Fe50Mn30Co10Cr10 high entropy alloy coatings with different NbC content were fabricated by laser cladding. The formation mechanism of NbC particles with micro/nano-scale was analyzed. Based on the interaction between the solid-liquid interface and NbC particles, the distribution of micro/nano-scale NbC particles is clarified. The effects of NbC content on microstructure and mechanical properties of the coatings were investigated. It demonstrated that the nanoscale NbC particles restricted the dendritic growth whilst promoting grain nucleation and altering the grain morphology from columnar grain to equiaxed dendrite. Besides, the influence of NbC particles on FCC phase stability was studied based on the lattice mismatch theory, which indicates that the addition of ceramic particles is a new way to modify the phase volume fraction in the dual-phase high-entropy alloys (HEA). The micro-hardness and wear resistance of the coatings significantly improved with the increase of NbC content. For the Fe50Mn30Co10Cr10-30 wt%NbC high entropy composite coating, the average Vickers hardness and friction coefficient value separately is 525 HV and 0.45. In addition, the large fluctuations on the friction coefficient of the coatings for 10 wt% and 20 wt% NbC addition may be related to the uneven distribution of nanoscale NbC particles in the matrix.

Deposition of graphene–copper composite film by cold spray from particles with graphene grown on copper particles

Graphene has been used to improve tribological property due to its extraordinary properties. For graphene composite, obtaining uniformly distributed and less damaged graphene is important for better improvement. In this research, graphene was fabricated on copper particle by thermal chemical vapor deposition to minimize structural damage and obtain uniform distribution. The obtained graphene-coated copper composite particle was deposited by cold spray which is less deteriorative for graphene. The scanning electron microscope images show that graphene appeared to surface of copper particle without any agglomeration. Raman spectrum indicates that mostly monolayer graphene was obtained. Uniform distribution of graphene was observed after the deposition by cold spray. Furthermore, the deposition by cold spray induced neglectable structural damages on graphene. Nevertheless 0.019 wt% of carbon corresponding to graphene was incorporated in the composite film, graphene improved tribological properties in comparison with those of the copper film; the average friction coefficient values were 0.60 and 0.46 for the copper and composite films, respectively, and the calculated specific wear rates of the films were 8.6 × 10−4 and 5.2 × 10−4 mm3/N∙m for the copper and graphene–copper composite films, respectively. The improved tribological properties resulted from the low shearing and passivation film by the incorporated graphene.

An Experimental Study on Wear Performance of Electrolytic Multilayer Cu-Ni-Cr Coated ABS Under Different Test Forces

Plastic materials are widely preferred in many applications due to being light and cheap in addition to being manufactured easily with various manufacturing methods like injection molding or additive manufacturing. One of the most used plastic material ABS (acrylonitrile butadiene styrene) is sometimes coated to increase its wear and corrosion resistance. In this study, investigating the effect of coating and test forces on wear behavior of injection-molded ABS specimens at room temperature were focused. For this purpose, ABS specimens were manufactured with injection molding technology and some samples were multilayer Cu-Ni-Cr coated step by step. Then, surface roughness values of prepared coated and uncoated specimens were measured by surface roughness profilometer. Subsequently, the micro view of the coated sample was obtained from an optical microscope after cutting the sample with the precision cutting machine. Lastly, the wear performance of coated and uncoated samples was tested under various loads such as 5N, 7N, and 10N by using pin-on-disc test equipment. In conclusion, surface roughness and wear level of samples were determined besides the average friction coefficient and friction forces. The results show that multilayer Cu-Ni-Cr coating affects the friction forces and average friction coefficient values significantly.

Ultrasonically developed silver/iota-carrageenan/cotton bionanocomposite as an efficient material for biomedical applications

In this approach, we assembled AgNps on cotton by using iota-carrageenan as a carbohydrate polymer under ultrasonic waves. UV–Vis spectroscopy revealed that iota-carrageenan free radicals increased the absorbance values of AgNps at 438 nm under ultrasonic vibration. We also observed an effective reduction of AgNps by color hue changes in the colloidal dispersions, ranging from pale to dark yellow. Interestingly, the zeta potential values for the AgNps changed from −8.5 to −45.7 mV after incorporation with iota-carrageenan. Moreover, iota-carrageenan reduced the average particle sizes of AgNps/iota-carrageenan nanocomposite particles. Fourier transform infrared (FTIR) spectra proved the successful fabrication of AgNps/iota-carrageenan/cotton nanocomposites by shifting two bands at 3257 and 990 cm−1. Quantum Chemistry and Molecular Dynamics demonstrated strong interactions between AgNps and iota-carrageenan by changes in the bond lengths for CC, CH, CO, SO. Furthermore, new energy levels were generated in iota-carrageenan's molecules by exciting electrons under ultrasonic vibration. According to the thermal gravimetric analysis (TGA) results, fabrication of AgNps/iota-carrageenan on cotton reduced the thermal stability of the resultant AgNps/iota-carrageenan/cotton nanocomposites. The average friction coefficient values of nanocomposite samples were increased in weft-to-warp direction that can be an advantage for wound healing, antimicrobial treatment and drug delivery applications. We did not observe reduction in the mechanical properties of our AgNps incorporated nanocomposites. Furthermore, the samples were tested for possible cytotoxicity against primary human skin fibroblast cells and no toxicity was observed.

Improvement of high entropy alloy nitride coatings (AlCrNbSiTiMo)N on mechanical and high temperature tribological properties by tuning substrate bias

High entropy alloy nitride coatings (HEAN), showing superior mechanical strength, high oxidation resistance, and thermal stability, have often been used in protective hard coatings field. However, the high temperature tribological field of novel HEA nitride films has not yet been well studied. The correlations among tribological properties, compressive residual stress, mechanical properties, and self-lubricating oxide are still limited.In this research, the novel (AlCrNbSiTiMo)N coatings were fabricated on both Inconel-718 and Si (100) substrate by radio frequency (RF) magnetron sputtering via tuning both substrate bias at 300 °C deposition temperature. The (AlCrNbSiTiMo)N coatings with a specific substrate bias exhibit an outstanding hardness of 34.5±0.8 GPa.In the wear test at 700 °C, the films deposited at −100 V revealed the lowest wear rate around 1.2 × 10−6 mm3N−1 m−1. With Molybdenum doping, the MoO3 Magnéli phase was observed on the surface at elevated temperature wearing process, and the friction coefficient at high temperature decreased significantly due to a lubricating surface. The coating exhibited the average friction coefficient value of 0.48 in the wear test of 700 °C. The high temperature tribological performance was addressed and related to the mechanical properties, the plastic deformation resistance H3/E2, and the excess residual stress of the films.This study provides a new design for hard coatings applied to severe wearing conditions. By tuning substrate bias, the (AlCrNbSiTiMo)N coatings exhibit outstanding mechanical and tribological characteristics, which will be a promising candidate for high temperature tribological protective film.

Friction in vacuum and under different gaseous environment of magnetized sliding ferromagnetic contact

The direct metal/metal sliding contact causes a severe wear with a high friction coefficient and an important wear rate. Applying magnetic field into the rotating sliding steel Fe360 B/steel Fe360 B modifies the friction and the wear behavior of the contact. The experimental tests were conducted in three different environments such as: ambient air, pure oxygen at 105 Pa and high vacuum at 5.10−5 Pa. In ambient air and without magnetic field, the metal/metal contact is ductile. When a magnetic field is applied, the formation of oxide layer evolves progressively with the number of sliding cycles. This contact has a low friction and mild wear. Under oxygen, the oxide film appears in wear track with and without applied magnetic field. The wear rate under oxygen is lower than that in ambient air with a ratio roughly equals to 10. In oxygen, the average value of friction coefficient µ decreases from µ = 0.41 to µ = 0.30. In vacuum, the increase of surface hardness causes a transfer of particles from the disc towards the pin. This transfer modifies the morphology of the wear track, increases the surfaces roughness and leads to a strong adhesive wear. The different analysis obtained with: microscopy, micro-harness, wear losses, EDX and friction evolution explains the effect of applied magnetic field on the friction behavior of Fe360 B steel.

Study of alkyl acrylate-co-maleic anhydride-based novel amide copolymers as multifunctional lubricant additives

Three novel multifunctional additives (MFAs), poly(alkyl acrylate-co-maleic anhydride)-based amide copolymers, were synthesized by the reaction between intermediate alkyl acrylate-co-maleic anhydride and three different amines, viz. octylamine (MFA 1), dodecylamine (MFA 2), and octadecylamine (MFA 3). Additives were successfully prepared by the polymerization route using benzoyl peroxide (Bz2O2) as a free radical initiator. Analytical techniques such as Fourier transform infrared, nuclear magnetic resonance, and gel permeation chromatography were used to characterize the synthesized polymeric compounds. Polyol was taken as reference base oil for performance evaluation of the synthesized polymers as multifunctional additive for viscosity index improver, pour point depressant, anti-wear, anti-friction, detergent–dispersant, and anti-corrosion properties. MFA 1 reflected the best performance as detergent–dispersant and anti-corrosive additive with observed increment of ~ 48% and ~ 54%, respectively, in comparison with blank polyol. MFA 3 showed the best viscosity index improving property which enhanced the viscosity index of polyol base oil from 191.85 to 250.45 at 3000 ppm. It also showed best tribological performance in 3000 ppm concentration at which the average wear scar diameter and average friction coefficient values decrease to 482 µm and 0.0823 from the 690 µm and 0.1276 for blank polyol.

EVALUATING SEIZURE ON FOUR BALL TESTER FOR RAPESEED OIL

This paper presents a tribological characterization in seizure regime for two lubricants (rapeseed oil and rapeseed oil additivated with 1%wt TiO2). Tests were done on a four-ball tester, in the load range at the tester shaft 500...900 N, in step of 50 N, for 60 seconds and with a rotational speed of 1400 rpm (equivalent to a sliding speed of 0.53 m/s). There were discussed the average value of friction coefficient, the wear scar diameter (WSD), the flash temperature parameter and several texture 3D parameters. Till 600 N, the influence of additivation is not obvious, the friction coefficient is lower for the neat oil, WSD is similar, but after this load, the slope for WSD is smaller for the additivated lubricant and for 900 N, this parameter is also smaller. Sa seems to be quite insensitive to the load increase, but other parameters, like St has a significant increase, meaning two processes: additive is pressed on the surface and developed high local peaks or/and the adhesive and abrasive wear is more intense. FTP is almost the same at 900 N, but the additive makes this parameter to evolve with a plateau with low slope, meaning the additivated lubricant has a better behavior under high loads.

Effect of particle weight concentration on the lubrication properties of graphene based epoxy composites

Epoxy-graphene composites are prepared with varying graphene concentration of 1 wt%, 3 wt%, and 5 wt%. Composite fabrication involves continuous stirring of the mixture consisting graphene and epoxy resin followed by curing first at room temperature and subsequently at 100 °C. In the epoxy-graphene composites, compressive stresses show increasing trend with filler concentration. A correlation between surface roughness and wetting is established to explain the Wenzel's contact model. Friction and wear behavior is evaluated under dry/lubricated contact. The average friction-coefficient values of 5 wt% epoxy-graphene composites range between 0.02 and 0.18, and 0.01–0.09 for dry and lubricated contact, respectively. Wear rate under dry and lubricated contact ranges between 0.95 and 3.15 × 10−7 and 0.67–2.21 × 10−7 mm3/N-m, respectively. Minimum dissipation energy of 5.1 × 102 N-m is obtained for 5 wt% epoxy-graphene composites. Functionalization of graphene and tribofilm formation lead to excellent properties in the prepared composites, and they are suitable for light-weight automotive application.

Dry Sliding Tribological Behavior of Columnar-Grained Fe2B Intermetallic Compound Under Different Loads

The dry sliding tribological behavior of a columnar-grained Fe2B intermetallic compound under different normal loads was evaluated by scanning electron microscopy (SEM), XPS, and 3D laser scanning microscope. The results indicated that under a load of 12 N, after a 35 min break-in period, the dynamic friction coefficient decreased from 0.78 to about 0.6 and this low value was maintained until the end of test. When the normal load increased from 4 N to 20 N, both the average friction coefficient and wear rate values initially decreased and then increased. The lowest values of the average friction coefficient and wear rate were obtained under a load of 12 N. As the load increased from 4 N to 12 N, a complete film formed on worn surface. Nevertheless, when the load increased to 16 N, severe self-induced vibration occurred and a corrugated ribbon appeared on the surface. Furthermore, severe damage on the worn surface was caused by cycling vibration under the 20 N load. Under 4 N and 12 N, the main wear mechanism was abrasive wear, while under a load of 20 N, fracture wear and abrasive wear were the mian wear mechanisms. The friction products were composed of B2O3, H3BO3, SiO2, and FexOy. More specifically, Fe2O3 was generated under 4 N load, Fe2O3 and Fe3O4 were produced under 12 N load, and the mixture of FeO, Fe2O3, and Fe3O4 appeared under 20 N load.

COMPARISON OF PLOUGHSHARE BOLTS HARDNESS AND COEFFICIENT OF FRICTION PROPERTIES

Parts working in soil are exposed to effects of different abrasive particules in soil. Hardness of the particules that is mostly higher than tools’ causes the tool to be worn or broken. The tools are made in detachable form in order to prevent to be broken. The form is mostly made with bolts and nuts. One of agricultural tools working in soil, Ploughshare is joined to plough beam with bolts. The galvanised bolts are manufactured in form of countersunk head and DIN 604 standard. In our study, hardness (HB) and friction coefficient (µ) of six different plough bolts are examined. The average values of friction coefficient are determined as 0.20, 0.24, 0.16, 0.12, 0.15, 0.18 and Hardness’ 121, 137, 105, 100, 101, 111 respectively.