Performance comparison of training algorithms for the estimation of B?hme abrasion resistance using neural networks

Natural stones used as floor and wall coverings are exposed to many different abrasive forces,so it is essential to choose suitable materials for wear resistance in terms of the life of the structure.The abrasion resistance of natural stones can be determined in the laboratory by applying the B?hme abrasion resistance(BAR)test.However,the direct analysis of BAR in the laboratory has disadvantages such as wasting time and energy,experimental errors,and health impacts.To eliminate these disadvantages,the estimation of BAR using artificial neural networks(ANN)was proposed.Different natural stone samples were collected from Türkiye,and uniaxial compressive strength(UCS),flexural strength(FS),water absorption rate(WA),unit volume weight(UW),effective porosity(n),and BAR tests were carried out.The outputs of these tests were gathered and a data set,consisting of a total of 105 data,was randomly divided into two groups:testing and training.In the current study,the success of three different training algorithms of Levenberg-Marquardt(LM),Bayesian regularization(BR),and scaled conjugate gradient(SCG)were compared for BAR prediction of natural stones.Statistical criteria such as coefficient of determination(R~2),mean square error(MSE),mean square error(RMSE),and mean absolute percentage error(MAPE),which are widely used and adopted in the literature,were used to determine predictive validity.The findings of the study indicated that ANN is a valid method for estimating the BAR value.Also,the LM algorithm(R~2=0.9999,MSE=0.0001,RMSE=0.0110,and MAPE=0.0487)in training and the BR algorithm(R~2=0.9896,MSE=0.0589,RMSE=0.2427,and MAPE=1.2327)in testing showed the best prediction performance.It has been observed that the proposed method is quite practical to implement.Using the artificial neural networks method will provide an advantage in similar laborintensive experimental studies.

Effects of nano-Al_2O_3 and nano-ZrO_2 on the microstructure, behavior and abrasive wear resistance of WC-8Co cemented carbide

WC-8wt.% Co cemented carbides with varied nano-Al 2 O 3 and nano-ZrO 2 contents were prepared respectively following conventional powder metallurgical procedures. Effects of nano-Al 2 O 3 and nano-ZrO 2 on the microstructure, behavior, and abrasive wear resistance were investigated. The result shows that a finer and more homogenous microstructure can be achieved by increasing nano-Al 2 O 3 , and increasing nano-ZrO 2 makes the microstructure more refined. Nano-Al 2 O 3 and nano-ZrO 2 could both help to give increased hardness. Transverse rupture strength is higher if the above nano-oxides are doped appropriately, whereas excess addition is deleterious. Abrasive wear resistance presents different variations with respect to increasing nano-Al 2 O 3 and nano-ZrO 2 . By contrast, increasing nano-ZrO 2 enhances the abrasive wear resistance more effectively than increasing nano-Al 2 O 3 . The influence of the two nano-oxides contents on the abrasive wear resistance does not almost vary with wear time, and the optimum addition level of nano-Al 2 O 3 in WC-8% Co cemented carbide is 0.3 wt.% from the stand of abrasive wear resistance. In addition, both of the nano-oxides can retard the increase of wear rate in long-term abrasive wear.

Abrasive resistance of metastable V–Cr–Mn–Ni spheroidal carbide cast irons using the factorial design method

Full factorial design was used to evaluate the two-body abrasive resistance of 3wt%C–4wt%Mn–1.5wt%Ni spheroidal carbide cast irons with varying vanadium（5.0wt%–10.0wt%） and chromium（up to 9.0wt%） contents. The alloys were quenched at 920℃. The regression equation of wear rate as a function of V and Cr contents was proposed. This regression equation shows that the wear rate decreases with increasing V content because of the growth of spheroidal VC carbide amount. Cr influences the overall response in a complex manner both by reducing the wear rate owing to eutectic carbides（M7C3） and by increasing the wear rate though stabilizing austenite to deformation-induced martensite transformation. This transformation is recognized as an important factor in increasing the abrasive response of the alloys. By analyzing the regression equation, the optimal content ranges are found to be 7.5wt%–10.0wt% for V and 2.5wt%–4.5wt% for Cr, which corresponds to the alloys containing 9vol%–15vol% spheroidal VC carbides, 8vol%–16vol% M7C3, and a metastable austenite/martensite matrix. The wear resistance is 1.9–2.3 times that of the traditional 12wt% V–13wt% Mn spheroidal carbide cast iron.

Relationship among wear-resistance of three-body abrasion, substructure and property in martensite steels

The effects of subsurface hardness on wear-resistance of martensitic steel20Cr, 40CrSi, 60Mn, T8 and T10 in three-body abrasion under static load was investigated. It showsthat the characteristic of the subsurface hardness distribution and the abrasive wear resistance isrelated to the substructure near the worn surface. The substructure of the tested martensite steelhas an apparent relationship with the carbon content and steels with moderate carbon content andhardness exhibit good resistance to abrasive wear. The competition of the work-hardening effect andthe temper softening effect, which resulted from deformation and friction heat generating duringabrasive wear is considered to be a main reason for the relation among wear-resistance, hardness andsubstructure. At the test conditions, the wear-resistance of 40CrSi is the best.

Influence of secondary carbide precipitation and transformation on abrasion resistance of a 3Cr15Mo1V1.5 white iron

The relationship between the secondary carbide precipitation and transformation of the 3Cr15Mo1V1.5 white iron and abrasion resistance was investigated by using optical microscope （OM）, transmission electron microscopy （TEM） and X-ray diffrac- tion （XRD）. The results show that the properties of secondary carbides precipitated at holding stage play an important role in the abrasion resistance. After certain holding time at 833 K subcritical treatment, the grainy （Fe, Cr）23C6 carbide precipitated and the fresh martensite transformed at the holding stage for 3Cr15Mo1V1.5 white iron improve the bulk hardness and abrasion resistance of the alloy. Prolonging holding time, MoC and （Cr, V）2C precipitations cause the secondary hardening peak and the corresponding better abrasion resistance. Finally, granular （Fe, Cr）23C6 carbide in situ transforms into laminar M3C carbide and the matrix structure transforms into pearlitic matrix. These changes weaken hardness and abrasion resistance of the alloy sharply.

Interface characteristics and wear resistance of Ni-B_(4)C plated ZTA reinforced high chromium cast iron composite

A chemical composite plating of Ni-B_(4)C was used to prepare the surface-modified zirconia toughened alumina(ZTA)ceramic particles.The ceramic preforms were prepared by the plated ZTA and sodium silicate solution binder,followed by casting infiltration to prepare the ZTA particles reinforced high chromium cast iron(HCCI)composites.The result reveals that a distinct interface layer forms at the ZTA/HCCI interface,which consists of phases of ZrB_(2),FeB,Fe_(2)B,and NaSiO_(4).The interfacial wettability between ZTA and HCCI is improved by the diffusion and reaction of Ni and B_(4)C.The wear test reveals that the Ni-B_(4)C plated ZTA particles can effectively improve the wear resistance of the ZTA/HCCI composite,and the wear rate of the composite is decreased to 11.6%of HCCI.

Influences of Polypropylene Fiber and SBR Polymer Latex on Abrasion Resistance of Cement Mortar

Influences of polypropylene （PP） fiber and styrene-butadiene rubber （SBR） polymer latex on the strength performance, abrasion resistance of cement mortar were studied. The experimental results show that the flexural strength, brittleness index （σF/σC） and abrasion resistance can be improved significantly by the addition of PP fiber and SBR polymer latex. The relationship between the flexural strength and abrasion resistance was analyzed, showing a good linear relationship between them. The reinforced mechanism of PP fiber and SBR polymer latex on cement mortar was analyzed by some microscopic tests. The test results show that the addition of SBR polymer latex has no significant influence on the cement hydration after 7 d curing. Adding SBR polymer latex into cement mortar can form a polymer transition layer in the interfaces of PP fiber and cement hydrates, which improves the bonding properties between the PP fiber and cement mortar matrix effectively.

The Abrasion-resistance Investigation of Rubberized Concrete

The abrasion resistance properties of rubberized concrete were comparatively studied by taking silica fume and crumb tire rubber as the additives. The abrasion tests were conducted in accordance with the Chinese standard test method DL/T 5150 - 2001, two recommended test methods： under water method and ring method, were used. The crumb tire rubbers with the sieve size of 8-mesh and 16-mesh were incorporated into the concrete by replacing same volume of sand and as an additive. The abrasion resistance of concrete was evaluated according to the abrasion resistance strength and the mass loss. Test results show that the addition of silica fume enhanced both compressive strength and abrasion resistance of concrete, and the addition of crumb rubber reduced the compressive strength but increased notably the abrasion resistance of the concrete. Silica fume concrete performed a better abrasion resistance than control concrete, and the rubberized concrete performed a much better abrasion resistance than silica fume concrete. The abrasion resistance of rubberized concrete increased with the increase of rubber content.

Relations of abrasion resistance and hardness of 16Cr-3C white irons with retained austenite content

The relationship between the retained austenite content of the matrix in16Cr-3C white irons and the abrasion resistance was investigated. The results show that: (1) theabrasion resistance can be improved by sub-critical heat treatment, which could be attributed to thedecrease of the retained austenite content; (2) both the abrasion resistance and hardness can beimproved by controlling the retained austenite content below 20 percent-30 percent and arrive at themaximum when the retained austenite content is reduced to about 10 percent; (3) the abrasionresistance decreases abruptly once the retained austenite content is lower than 10 percent, whichstems from both the in situ transformation of (Fe, Cr)_(23)C_6 to M_3C carbides and the formation ofpearlitic matrix.

Addressing the Fuel Resistance of Hot Mix Asphalt by an Enhanced Test Method

In areas where hot mix asphalt(HMA)is likely to be exposed by any form of mineral oil the layer has to withstand the attack of these substances in order not to damage the construction.The European Standard EN 12697-43 provides a test procedure to determine the resistance of HMA to fuel.The paper reviews this method thoroughly.A completely revised and simplified test device for the brush test was developed meeting the requirements of the standard and creating results with a high repeatability at the same time.The test conditions given by the standard such as the exposure to fuel,cleaning of the specimen after exposure or the contact pressure of the brush were varied to isolate those test conditions with a substantial influence on the result.The research revealed that in the standard some conditions with a rather small influence are set quite strictly while other conditions with a distinct influence on the result are not defined with the required accuracy to obtain comparable and repeatable results.The paper presents suggestions for the improvement of the test method and the standard itself in respect to the layout of the test device and the definition of important test conditions to enhance the outcome of the EN 12697-43.

Study on Abrasion Resistance of Modified Polypropylene Fiber Reinforced Cement

Modified polypropylene fiber reinforced cement compos-ites were investigated in their abrasion resistance andsurface morphology. The test results showed the addingof fiber could noticeably improve the abrasion resistanceof composite. The bonding and friction of fibers/cementwere the main contribution to abrasion resistance im-provement, which resulted from the surface morphologyobservation.

Research of Test Method on Abrasion Resistance at Elevated Temperatures of Refractories

In this work,the factors and parameters of a test method on abrasion resistance at elevated temperatures were discussed and researched.First of all,the precision tests of the test method on abrasion resistance at elevated temperatures were conducted in 8 laboratories.The results such as the standard deviation and reproducibility show good repeatability and reliability.The relationship between the stability of refractory performance and the standard deviation of their wear value was analyzed.Then the impact of the heat treatment condition of unshaped refractories and oxidation of SiC sand as abrasive on the lost volume of the tested specimens was researched.

A New Test Method for Hot Abrasion Resistance on Refractories

Test methods for hot abrasion resistance of refractories in China and overseas were briefly introduced. A new test method for hot abrasion resistance was researched. The new method inherits test principle of cold abrasion resistance in Chinese standard totally, adopts compressed air pre-heating and electricity heating sam- ples, and is featured with complete structure, good con- trollability, simple operation, and small size. The characteristics and operating procedure of HAT-14A tester were introduced. The hot abrasion resistance of various refractories at different temperatures was tested.

Abrasion Resistance of Cement Paste with Granulated Blast Furnace Slag and Its Relations to Microhardness and Microstructure

The abrasion resistance of cement pastes with 30 wt%,40 wt%and 50 wt%granulated blast furnace slag(GBFS),and its relations to microhardness and microstructure like hydration products and pore structure were studied.Results indicated that GBFS decreased the abrasion resistance of paste,and among the pastes with GBFS,the paste with 40 wt%GBFS showed the highest abrasion resistance.The microhardness of GBFS was lower than that of the cement,and the microhardness of the hydration products in paste with GBFS was also lower than that of the hydration products in paste without GBFS,so that the abrasion resistance of paste decreased when GBFS was incorporated.The reason for the decrease of microhardness of pastes with GBFS was that the contents of Ca(OH)_(2)in pastes with GBFS was significantly lower than that in the paste without GBFS,while large amounts of calcium aluminate hydrates and hydrotalcite-like phases(HT)in pastes with GBFS were generated.Furthermore,among the pastes with GBFS,the paste with 40 wt%GBFS showed the lowest porosity which was the main reason for its highest abrasion resistance.

Effect of the CaF_2-fraction in the glass-ceramic with abrasion resistance on crystallization

Investigated the effect of an addition of CaF2 on the crystallization of a glass-ceramic with abrasion resistance. X-ray diffraction, differential thermal analysis and scanning electron microscopy were used to determine the effect. The results showed that a suitable addition of CaF2 promoted crystallization by forming an interme- diate crystalline phase. CaF2 can decrease the temperature and active energy of the base-glass for crystallization. When 4 mass-% of CaF2-fraction is added in the glass, the crystallization temperature and active energy is 936 ℃and 172.75 kJ/mol respectively. When CaF2 is increased to 6 mass-%, the temperature and active energy decrease to 890 ℃ and 88.81 kJ/mol. CaF2 is an efficient nucleating agent for the glass-ceramics with abrasion resistant, the optimal content of CaF2 is about 6 mass-%.

Mechanism of C_(4)AF Content and Heat-curing Process on the Abrasion Resistance of High Ferrite Cement

Cement used in severe maritime environments must be attached with exceptional properties such as high sulfate resistance and abrasion strength.A sulfate resistant material typically used in marine engineering is high ferrite cement,which has been utilized in sulfate-rich environments.This study aims at exploring the effect of C_(4)AF and heat-curing on the abrasion resistance of high ferrite cement(HFC,C_(4)AF:14%-22%)in order to have a comprehensive understanding of this mechanism and promote the application of HFC in marine engineering.A new invention was designed for the abrasion resistance device by considering the sea-wave abrasion and seawater erosion in laboratory.The compressive strength and abrasion resistance of HFC were measured.Additionally,advanced analytical methods were used to explore the abrasion resistance mechanism of HFC,including X-ray fluorescence(XRF),X-ray diffraction(XRD),and thermogravimetric(TG)analyses,as well as mercury intrusion porosimetry(MIP).The results showed that HFC had the best abrasion resistance under appropriate heat-curing system that the curing temperature was 50℃and the hosting time was 4 hours,compared with PI(Portland cement)and LHC(low heat cement),meanwhile the abrasion resistance of HFC had a 62.4%increase when C_(4)AF content is increased from 14%to 22%.It can be ascribed that the content of portlandite is decreased due to the increase of C_(4)AF,which can reduce the portlandite assembled in ITZ(interfacial transition zone).It can also be ascribed that the DEF(delayed ettringite formation)is successfully avoided in HFC and the hydration degree of HFC can continue to be boosted under appropriate heat-curing system.

Multiple Response Optimization of Three-Body Abrasive Wear Behaviour of Graphite Filled Carbon-Epoxy ComPosites Using Grey-Based Taguchi Approach

The three-body abrasive wear behaviour of carbon fabric reinforced epoxy (C-E) composites has been evaluated by the addition of graphite (G) particles as a secondary reinforcement. Three-body abrasive wear test were conducted using dry sand rubber wheel abrasion tester as per ASTM G-65 with three process parameters load, abrading distance and filler content. To assess the abrasive wear behaviour of particulate filled C-E composites satisfying multiple performance measure, grey-based Taguchi approach has been adopted. The experiments were designed according to Taguchi’s orthogonal array (L?27). The grey relational analysis was applied to convert a multi response process optimization to a single response. Using analysis of variance, significant contributions of process parameters have been determined. The results indicate that the addition of graphite particles into C-E composite increased the wear resistance considerably. It was observed that highest wear resistance of C-E composite was achieved with incorporation of 10 wt. % of graphite filler. Results indicate that the filler content and grit size of abrasive paper were found to be the most significant factor which has influence on the abrasive wear of C-E composite. The worn surface features were examined through scanning electron microscope to probe the wear mechanism.

Compressive Strength and Abrasion Resistance of Concretes under Varying Exposure Conditions

The purpose of this study is to comparatively evaluate the wear resistance of concretes under abrasion rates. Five concrete mix proportions of a fixed water-cement ratio of 0.45 were considered in the study, but the constituent materials, age of concrete and exposure contact conditions were varied. The coarse aggregate type employed in the study was crushed granite. The compressive strength and abrasion resistance of concretes were tested between at ages 7 to 70 days and 100 - 500 revolutions of abrasion wheels respectively. The study revealed that the compressive strength and abrasion resistance had the optimal performance when the coarse aggregate content was 45% and the worst performance when the fine aggregate content was 28.7% of the total weight of concrete constituents. There was a remarkable loss of concrete particles to wear between 200 revs and 300 revs of abrasion wheel contact. Concrete grade in excess of 60 N/mm2 is required to resist abrasion beyond 200 revolutions of abrasion wheel contact on concrete specimens. Concretes investigated also showed weak resistance to deep abrasion at and above 300 revolutions of abrasion wheel contact.

Enhancing Mar and Abrasion Resistance of Acrylic Hard Coatings with Soft Base Layer

Mar and abrasion resistance were investigated by a progressive load scratch test and steel wool abrasion test, respectively. Two acrylic coating systems including trimethylolpropane triacrylate (TMPTA) and pentaerythritol triacrylate (PETA) were prepared. A soft base layer was introduced as an intermediate layer between two different types of top layer and poly (methyl methacrylate) (PMMA) substrate to demonstrate the effect of soft base layer on mar and abrasion resistance. Abrasion damage on the coating surface was found to be less severe, when the soft base layer was incorporated into the coating systems. The reduction in scratch coefficient of friction (SCOF) and surface roughness was also observed. The results suggested that mar and abrasion resistance was greatly influenced by the presence of soft base layer, although different top layers were used. Moreover, it was found that abrasion resistance was further improved as the thicker soft base layer was applied.

Chinese Standards on Refractories Refractory Products-Determination of Abrasion Resistance at Ambient Temperature GB/T 18301-2012

This standard specifies the terms and definitions, theory, apparatus, specimens, test procedures, calcu- lation results, apparatus check and test reports, etc. of abrasion resistance at ambient temperature of refractory products.