Research on the Milling Toughness of Black Silicon Carbide and the Repeatability of the Testing Results

2011 ◽  
Vol 487 ◽  
pp. 225-228 ◽  
Author(s):  
M. Liu ◽  
S.J. Jiang
Keyword(s):  
Silicon Carbide ◽  
Test Methods ◽  
National Standard ◽  
Black Silicon ◽  
Milling Machine ◽  
Test Results ◽  
Testing Methods ◽  
Factors Affecting ◽  
Steel Balls ◽  
Ball Mass

The toughness of abrasive grits means their resistance against breaking under the effect of cutting forces. The commonly used test methods include single crystal static compressing, rolling crushing, mould pressing, as well as milling. In the national standard “GB/T 23538-2009 Conventional Abrasive Testing Methods for Toughness (ball mill method)”, it is stipulated that milling machine is to be used for the abrasive grits F8-F150 to determine their toughness. This method by milling includes testing steps as follows: take a certain amount of abrasive grits , together with steel balls of certain size and certain mass, into the ball milling machine rotating at a certain speed .When the specified total rotations are completed, measure the ratio of the unbroken grits to the total amount of the milled samples. This ratio is defined as the milling toughness of the abrasive grits. In this paper, the milling toughness of different sized black silicon carbide is tested according to the requirement of “GB /T 23538-2009”, and the repeatability of the testing results characterized by test standard deviation is discussed. The test results from different operators using different ball mass are compared and analyzed, and the factors affecting the milling toughness test results are researched. Some suggestions to improve the repeatability of the test results are given.

scholarly journals Evaluation of Bleeding Resistance in Chip Seal and Asphalt Emulsion Residue Rheology

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 670
Author(s):  
Preeda Chaturabong
Keyword(s):  
Influence Factors ◽  
Application Rate ◽  
Test Methods ◽  
Test Results ◽  
Asphalt Emulsion ◽  
Aggregate Gradation ◽  
Factors Affecting ◽  
Promising Tool ◽  
Chip Seal ◽  
Asphalt Emulsions

Chip seal bleeding is influenced by many factors, including design inputs, material properties, and project-specific conditions. It reduces the surface texture of the pavement and thus compromises the safety of the traveling public. Even though factors that bring about premature bleeding are known, currently, no laboratory test methods for evaluating bleeding in chip seals have been specified. The objective of this paper is to present the results of an investigation of the influence factors of asphalt emulsion residue properties measured by the ASTM D7405 multiple stress creep and recovery (MSCR) test, as well as other factors related to chip seal bleeding resistance as measured by the modified loaded wheel test (MLWT). In this study, the MSCR test was used as a tool for evaluating the performance of asphalt emulsions because it has been identified as a potential test related to bleeding in the field. In addition, MLWT was selected as a tool for evaluating chip seal bleeding performance in the laboratory. The results of the MLWT showed that the emulsion application rate (EAR), aggregate gradation, and emulsion properties were significant factors affecting bleeding. The MSCR test was found to be a promising tool for the performance evaluation of asphalt emulsion residue, as the test was able to differentiate between emulsion chemistries and modifications in terms of sensitivity to both temperature and stress. In relation to chip seal bleeding resistance, only the creep compliance (Jnr) obtained from the MSCR test results was identified as a significant property affecting potential for bleeding.

The Analysis on Materials Testing Network of Ecology Environment

2012 ◽  
Vol 427 ◽  
pp. 179-184
Author(s):  
Xin Chun Fang ◽  
Jian Zhong Sun ◽  
Rui Ping Kong ◽  
Lu Kui Shi
Keyword(s):  
Network Performance ◽  
Functional Materials ◽  
Test Methods ◽  
User Needs ◽  
Materials Testing ◽  
Network Technology ◽  
Test Results ◽  
Testing Methods ◽  
Network Testing ◽  
Balance Testing

As the network technology is widely used in the functional materials test of ecology environment, it becomes more and more important to balance testing network performance fast and accurately. However, there are so many network testing methods with a variety of user needs and different scopes. If we use these test methods indiscriminately, time and money is largely consumed, and the testing results often cannot meet user's requirements. Thus, while testing the network performance, in order to accelerate the speed of the material testing, and ensure the quality and the accuracy of test results, characteristics and user's requirements must be selected and improved.

scholarly journals Correlations Among Various Self-Consolidating Concrete Workability Responses

2012 ◽  
Vol 6 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Wu-Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing
Keyword(s):  
Mechanical Vibration ◽  
Maximum Size ◽  
Test Methods ◽  
Test Results ◽  
Testing Methods ◽  
Self Consolidating Concrete ◽  
Filling Ability ◽  
Crushed Aggregate ◽  
Class F Fly Ash ◽  
Passing Ability

Self-consolidating concrete (SCC) mixtures designated for precast, prestressed applications should be highly workable to flow easily through restricted spacing and completely encapsulate reinforcements without any mechanical vibration. Key workability characteristics of SCC can be described in terms of filling ability, passing ability, and resistance to segregation. These properties are typically characterized by data that relate to specific testing methods. In general, these methods include the components required for evaluating simultaneously filling ability, passing ability, and resistance to segregation, since these properties are rather interrelated. In this investigation, 33 SCC mixtures made with various mixture proportioning parameters, including maximum size and type of aggregate, type and content of binder, and w/cm were evaluated. The mixtures were prepared using crushed aggregate and gravel of three different nominal sizes, w/cm of 0.33 and 0.38, and three binder compositions: Type MS cement, Type HE cement with 30% of slag replacement, and Type HE cement with 20% of Class F fly ash. Comparisons and correlations among various test results used in evaluating the workability responses obtained for these mixtures are established. This is done to highlight advantages and limitations of the various test methods that can be used to assess workability of SCC designated for prestressed applications. Appropriate combinations of test methods that can be used to assess workability of SCC at the precast plant are recommended, and ranges of acceptance of the various test methods are established.

Combinations of Various Self-Consolidating Concrete Test Methods and Workability Responses

2010 ◽  
Vol 150-151 ◽  
pp. 18-22
Author(s):  
Wu Jian Long ◽  
Kamal Henri Khayat ◽  
Feng Xing
Keyword(s):  
Maximum Size ◽  
Test Methods ◽  
Test Results ◽  
Testing Methods ◽  
Mixture Proportioning ◽  
Self Consolidating Concrete ◽  
Filling Ability ◽  
Passing Ability

Key workability characteristics of SCC can be described in terms of filling ability, passing ability, and resistance to segregation. These properties are typically characterized by data that relate to specific testing methods. In general, these methods include the components required for evaluating simultaneously filling ability, passing ability, and resistance to segregation, since these properties are rather interrelated. In this investigation, 33 SCC mixtures made with various mixture proportioning parameters, including maximum size and type of aggregate, type and content of binder, and w/cm were evaluated. Comparisons and correlations among various test results used in evaluating the workability responses obtained for these mixtures are established. This is done to highlight advantages and limitations of the various test methods that can be used to assess workability of SCC designated for precast, prestressed applications. Ranges of acceptance of the various test methods are also established.

A Literature Review on Alkali Silica Reactivity of Concrete

2018 ◽  
Vol 1 (2) ◽  
pp. 43-62 ◽  
Author(s):  
Muhammad Junaid Munir ◽  
Syed Minhaj Saleem Kazmi ◽  
Yu-Fei Wu ◽  
Indubhushan Patnaikuni
Keyword(s):  
Literature Review ◽  
Preventive Measures ◽  
Test Methods ◽  
Alkali Silica Reaction ◽  
Alkali Content ◽  
Testing Methods ◽  
Factors Affecting ◽  
Testing Conditions ◽  
Alkali Silica Reactivity ◽  
Vast Literature

Deterioration of concrete structures with time is well understood. One of the major reasons of deterioration is reaction between cement paste and reactive siliceous aggregates which is known as alkali silica reaction (ASR). This article reviews the studies on ASR in concrete. Although a vast literature is available on mechanisms and preventive measures against ASR, however there are still a lot of deficiencies regarding the test methods to detect the ASR potential in concrete. The aim of this article is to discuss different factors affecting ASR, consequences of ASR and different challenges encountered by researchers in the detection of ASR. The study revealed that alkali content of cement, aggregates grading, mineralogical combinations, testing methods and testing conditions are all the challenges, researchers face during evaluation of ASR potential in concrete.

TEST METHODS FOR POLYORGANOSILOXANE COMPOSITIONS USED AS PROTECTIVE COATINGS IN ELECTRONIC INSTRUMENTATION

2020 ◽  
Author(s):  
Ольга Владимировна Неёлова ◽  
Людмила Муратовна Кубалова ◽  
Анна Петровна Деревщикова
Keyword(s):  
Protective Coatings ◽  
Test Methods ◽  
Testing Methods ◽  
Organosilicon Polymer ◽  
Electronic Instrumentation

Представлен обзор по методам испытаний кремний органических полимерных композиций, применяемых в качестве защитных покрытий в современном электронном приборостроении. A review is given of testing methods for organosilicon polymer compositions used as protective coatings in modern electronic instrumentation.

Analisa Pengujian Repeatability Timbangan Elektronik dengan Metode Syarat Teknis Timbangan Non Otomatis dan Metode NMI Australia

2019 ◽  
Vol 4 (2) ◽  
pp. 176-183
Author(s):  
Ponco Wali
Keyword(s):  
Research Method ◽  
Test Methods ◽  
Test Results ◽  
Repeat Testing ◽  
Testing Method ◽  
Technical Requirements

Testing repeat electronic scales with non-automatic scales technical requirements so far is fairly long if not using a calculator or computer. The aim of this research is to compare the repeatability testing method of electronic scales using methods according to the technical requirements of non-automatic scales and the Australian NMI method, both of which refer to OIML R76 in determining the validity or cancellation of electronic scales repeatability testing. This research method is done through repeat testing on 3 samples of electronic scales, then on each electronic scale 2 test methods are performed. The conclusion is that the electronic scales repeatability testing uses the non-automatic scales technical requirements method and the Australian NMI method has some differences although both refer to OIML R76. These differences include several points, namely the charge used, the method of adding additions, the formula for determining electronic scales, and different test results. The Australian NMI method is deemed to make it easier and more time efficient compared to the non-automatic weighing technical requirements method.

Improving the Strength of Abrasive Wheels and Optimizing the Control over the Strength of Composite Abrasive Materials

2019 ◽  
Vol 946 ◽  
pp. 380-385
Author(s):  
Boris A. Chaplygin ◽  
Viacheslav V. Shirokov ◽  
Tat'yana A. Lisovskaya ◽  
Roman A. Lisovskiy
Keyword(s):  
Mechanical Properties ◽  
Test Results ◽  
Key Factors ◽  
Special Equipment ◽  
Material Density ◽  
Factors Affecting ◽  
Control Factors ◽  
Reinforcing Material ◽  
Special Studies ◽  
First Time

The strength of abrasive wheels is one of the key factors affecting the performance of abrasive machining. The paper discusses ways to improve the strength of abrasive wheels. The stress-state mathematical model presented herein is a generalization of the existing models. It is used herein to find for the first time that there are numerous optimal combinations of the elastic modulus and reinforcing material density, which result in the same minimum value of the objective function. It is found out that increasing the radius of the reinforcing component while also optimizing the mechanical properties of its material may increase the permissible breaking speed of the wheel several times. We herein present a regression equation and a nomogram for finding the optimal combination of control factors. Conventional methods for testing the mechanical properties of materials, which have been proven reliable for testing metals and alloys, are not as reliable for testing abrasive materials, as the test results they generate are not sufficiently stable or accurate. We therefore propose an alternative method that does not require any special equipment or special studies.

Research the Test Method of the Voltage Transformer Secondary Load in the Three-Phase Three-Wire Electric Energy Metering Device

2014 ◽  
Vol 687-691 ◽  
pp. 3110-3115
Author(s):  
Gu Li ◽  
Zi Ming Fu ◽  
Jie Feng Yan ◽  
Bing Wen Li ◽  
Zhi Rong Cen
Keyword(s):  
Power Supply System ◽  
Electric Energy ◽  
Test Methods ◽  
Test Method ◽  
Testing Methods ◽  
Voltage Transformer ◽  
Secondary Load ◽  
Three Phase ◽  
Energy Metering ◽  
Definition Of

This paper analyzes and studies the definition of the voltage transformer secondary load, examines the practical purposes of the measured values of the voltage transformer secondary load, and presents a variety of testing methods to analyze and compare the differences. This paper gives the test methods of the voltage transformer secondary load when the connection of the voltage transformer is the Y / Y in a three-phase three-wire power supply system, filling the blank of this type of test method in the industry. When other units within the industry carry out such work, the conclusions of this paper are available for reference, and the conclusions of this paper can be referred when drafting relevant regulations in the future.

Shock Test and Acceleration Analysis Methods of Marine Diesel Engines to Underwater Explosions

2013 ◽  
Vol 345 ◽  
pp. 64-67
Author(s):  
Jian Hua Zhao ◽  
Rui Bo Zhang ◽  
De Bin Zhu ◽  
Hong Bin Gao
Keyword(s):  
Diesel Engine ◽  
Low Frequency ◽  
Vibration Signal ◽  
Test Methods ◽  
Shock Acceleration ◽  
Test Results ◽  
Shock Test ◽  
Marine Diesel ◽  
Reduction Methods ◽  
Acceleration Analysis

Shock test of marine diesel engine is the important content for ship anti-shock research. Plentiful shock tests of equipments have been carried out abroad, but there is no detailed test methods of diesel engine. According to simulation results, 8-channel acceleration test points are determined. Because diesel engine is working, the measured shock acceleration is interfered by vibration signal. Orthogonal wavelet decomposition and wavelet noise reduction methods are used to separate shock component from test results. The seperated shock component consists of two parts. One is the low-frequency part caused by the shock from diesel foundation and then attenuation through the isolator, the other is the high-frequency part caused by the secondary shock of the retainer.

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