scholarly journals STUDI KARAKTERISTIK MATERIAL STEM SEPEDA UNTUK PENGEMBANGAN PROTOTIPE STEM SEPEDA BERBASIS LIMBAH PISTON DENGAN VARIASI TEMPERATUR CETAKAN

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Cecep Suganda ◽  
Edi Sutoyo ◽  
Dwi Yuliaji
Keyword(s):  
Room Temperature ◽  
Hardness Test ◽  
Mold Temperature ◽  
Material Characteristic ◽  
Micro Structure ◽  
Average Hardness ◽  
Before And After ◽  
Characteristic Values ◽  
Hardness Values

<p>Bicycle stem is the link between handlebar (handlebar) with steerer tube (fork). Stem one of the bike parts to<br />note and Each type of bike is different for the size and specifications stemnya. This research aims to. Obtained<br />characterization of alumunium casting material as a material for making stem bikes with casting temperature of<br />700 ° C, and temperature variations of room temperature (30 ° C), 100 ° C, 150 ° C, 200 ° C, and characteristic<br />hardness values stem between piston waste material and stem. The piston waste is melted at the melting<br />furnace at a temperature of 700 ° C. then cast into the mold. After obtaining the specimen and then testing the<br />material characteristics include chemical composition, microstructure, and hardness. The result of the research<br />after casting with variation of the molded temperture has different material characteristic values, ie: chemical<br />composition which has no change before and after casting, the microt structure has little porous defect, and the<br />hardness value where the higher the mold temperature the lower the hardness . Conclusions of data processing<br />The highest value of piston recycled hardness is 93 HV when compared to the hardness of 61.2 HV stem bike<br />material, the hardness is more than enough and from the composition test there is a difference of Si 12%<br />composition. Result of micro structure at foundry with 4 variation still have defect of cast (porous and<br />shrinkage). the stam bike hardness test has an average hardness value of 64.2 HV whereas for the hardness<br />value of piston waste casting results show the hardness value of 91 HV with mold temperature 30 ° C, 93 HV<br />with mold temperture 100 ° C, 89 HV with mold temperature 150 ° C, 87 HV with mold temperature 200 ° C. The<br />higher the mold temperature, the lower the hardness of the material.</p>

scholarly journals Influence of Different Pigmentations and Accelerated Aging on the Hardness and Tear Strength of the A-2186 and MDX4-4210 Silicones

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Estefânia Marrega Malavazi ◽  
Daniela Micheline dos Santos ◽  
Clóvis Lamartine de Moraes Melo Neto ◽  
Fernanda Pereira de Caxias ◽  
Emily Vivianne Freitas da Silva ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Repeated Measures ◽  
Accelerated Aging ◽  
Hardness Test ◽  
Strength Test ◽  
Tear Strength ◽  
Tukey Test ◽  
Repeated Measures Analysis ◽  
Before And After ◽  
Hardness Values

Objective. To evaluate the influence of different pigmentations and accelerated aging on the hardness and tear strength of the A-2186 and MDX4-4210 silicones. Materials and Methods. The samples A-2186 and MDX4-4210 were manufactured without and with pigmentations (black, bronze, and pink). For the Shore A hardness test, 80 samples of each silicone were fabricated, and for the tear strength test, 320 samples of each silicone were fabricated. Eight groups were created for each test (n = 10). These tests were performed before and after 252, 504, and 1008 hours of aging. Three-way repeated-measures analysis of variance and the Tukey test were performed (α = 0.05). Results. The A-2186 silicone showed higher hardness and tear strength when compared with the MDX4-4210 silicone p<0.05, except in the hardness of the A-2186 and MDX4-4210 groups without pigmentation after 1008 hours p>0.05. All hardness values were between 25 and 35 units, regardless of the silicone type, period, and pigmentation (or no pigmentation). In most situations, the hardness of silicones used increased after 252 hours p<0.05. The nonpigmented MDX4-4210 group and all A-2186 groups showed an increase in tear strength after 252 hours p<0.05. For the nonpigmented MDX4-4210 group, from 252 to 1008 hours, there was no change in tear strength p>0.05. All pigmented MDX4-4210 groups showed no change in tear strength from 0 (initial) to 1008 hours of aging p>0.05. In all A-2186 groups, from 252 to 504 hours, there was a reduction in tear strength p<0.05, and from 504 to 1008 hours, there was an increase in tear strength p<0.05, except in the bronze A-2186 group p>0.05. Conclusion. In most situations, the A-2186 silicone showed significantly higher values of hardness and tear strength than the MDX4-4210 silicone. All hardness values were considered clinically acceptable. Accelerated aging could increase, decrease, or not significantly change the hardness and tear strength of the silicones used. The results of hardness and tear strength suggest that MDX4-4210 was more influenced by the presence of pigmentation after aging.

Preparation and Properties of UV-Curable Adhesives Based on Epoxy Acrylate Prepolymers

2011 ◽  
Vol 418-420 ◽  
pp. 1444-1447
Author(s):  
Yi Chi Chen ◽  
Tao He ◽  
Wei Yang ◽  
Li Qun Zhu ◽  
Wei Ping Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Uv Curing ◽  
Gel Permeation Chromatography ◽  
Epoxy Acrylate ◽  
Uv Curable ◽  
Gel Permeation ◽  
Before And After ◽  
Thermal Stability Of ◽  
Different Molecular Weight

Three kinds of commercially available epoxy acrylate reactive prepolymers with different molecular weight (MW) were used to formulate the UV-curable adhesives by addition of photo-initiator, reactive diluent, crosslinker and other additives as necessary. The MW of the said prepolymers were measured by gel permeation chromatography (GPC), while the structural characterization of the prepolymers before and after UV-curing was made by FTIR. Thermal stability of two kinds of UV-cured prepolymers with distinct MW and MW distribution was detected by thermogravimetric (TG) analysis.Lap shear strength of the adherents at different temperature were tested and compared with a known superior UV-curable adhesive (Loctite 3493). Adhesion strength of the adhesives at room temperature were all higher than 15 MPa which were more than the reported riveting intensity (10.3 MPa).

scholarly journals A Dislocation-scale Characterization of the Evolution of Deformation Microstructures around Nanoindentation Imprints in a TiAl Alloy

2018 ◽  
Author(s):  
Antoine Guitton ◽  
Hana Kriaa ◽  
Emmanuel Bouzy ◽  
Julien Guyon ◽  
Nabila Maloufi
Keyword(s):  
Plastic Deformation ◽  
Room Temperature ◽  
Tial Alloy ◽  
Mechanical Twinning ◽  
Contrast Imaging ◽  
Electron Channeling ◽  
The Poor ◽  
Before And After ◽  
Scale Characterization

In this work, plastic deformation was locally introduced at room temperature by nanoindentation on a &gamma;-TiAl based alloy. Comprehensive analyzes of microstructures were performed before and after deformation. In particular, the Burgers vectors, the line directions and the mechanical twinning systems were studied via accurate electron channeling contrast imaging. Accommodation of the deformation are reported and a scenario is proposed. All features help to explain the poor ductility of the TiAl based alloys at room temperature.

scholarly journals A Dislocation-Scale Characterization of the Evolution of Deformation Microstructures around Nanoindentation Imprints in a TiAl alloy

2018 ◽  
Author(s):  
Antoine Guitton ◽  
Hana Kriaa ◽  
Emmanuel Bouzy ◽  
Julien Guyon ◽  
Nabila Maloufi
Keyword(s):  
Plastic Deformation ◽  
Room Temperature ◽  
Tial Alloy ◽  
Mechanical Twinning ◽  
Contrast Imaging ◽  
Electron Channeling ◽  
The Poor ◽  
Before And After ◽  
Scale Characterization

In this work, plastic deformation was locally introduced at room temperature by nanoindentation on a &gamma;-TiAl based alloy. Comprehensive analyzes of microstructures were performed before and after deformation. In particular, the Burgers vectors, the line directions and the mechanical twinning systems were studied via accurate electron channeling contrast imaging. Accommodation of the deformation are reported and a scenario is proposed. All features help to explain the poor ductility of the TiAl based alloys at room temperature.

scholarly journals Effect of Cooling Media on Steel Hardness ST 37 of Conventional Lathe Process

2018 ◽  
Author(s):  
Teknomekanik ◽  
Nelvi Erizon ◽  
M. Iksan Ardiyansyah ◽  
Jasman ◽  
Yufrizal. A
Keyword(s):  
Oil Content ◽  
Hardness Test ◽  
Air Cooling ◽  
Hardness Tester ◽  
Cooling Medium ◽  
Average Hardness ◽  
Spindle Rotation ◽  
Boring Tool ◽  
Cooling Media ◽  
Hardness Values

This study aims to determine the type of air cooling media, soluble oil, and air to the result on lathe ST 37 steel. The cooling medium is very important to maintain boring tool deformation and can add product quality. In the process lathe of friction between the workpiece and chisel cut that can produce overheating and influence on the result of the slice boring tool on the workpiece. The research that will be carried out is experimental research with variables that are controlled that is feeding, deep of a cut, and spindle rotation and examination of the hardness of the specimen on the object before done lathe. The sample in this study which is ST 37 steel with diameter 25 mm and length 60 mm as many as 9 specimens which will be done lathe with different type media kind inprocess working. To know influence the type of cooling medium against steel ST 37 is done brinnel hardeness test using test equipment hardness tester. Of the 9 specimens lathe will be determined 3 points to do hardeness tests. From the result of hardness test and analysis obtained from hardness test on steel ST 37 average data that is use of soluble refrigerant media that produce a very good cooling at the time of the lathe process. The results of research is obtained that the use of soluble refrigerant media is the best with an average hardness of 224.10 kg / mm². On the lathe process, the cooling media has oil content will be able to maintain the scores hardness and time-worn on boring tool. Thus to maintain the hardness values can be used soluble oil cooling media and to increase the hardness values of workpieces can be used air cooling media.

scholarly journals Effect of Cooling Media on Steel Hardness ST 37 On Conventional Lathe Process

Teknomekanik ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 6-11
Author(s):  
Nelvi Erizon ◽  
M Iksan Ardiyansyah ◽  
Jasman Jasman ◽  
Yufrizal A
Keyword(s):  
Oil Content ◽  
Hardness Test ◽  
Air Cooling ◽  
Hardness Tester ◽  
Cooling Medium ◽  
Average Hardness ◽  
Spindle Rotation ◽  
Boring Tool ◽  
Cooling Media ◽  
Hardness Values

This study aims to determine the type of air cooling media, soluble oil, and air to the result on lathe ST 37 steel. The cooling medium is very important to maintain boring tool deformation and can add product quality. In the process lathe of friction between the workpiece and chisel cut that can produce overheating and influence on the result of the slice boring tool on the workpiece. The research that will be carried out is experimental research with variables that are controlled that is feeding, deep of a cut, and spindle rotation and examination of the hardness of the specimen on the object before done lathe. The sample in this study which is ST 37 steel with diameter 25 mm and length 60 mm as many as 9 specimens which will be done lathe with different type media kind inprocess working. To know influence the type of cooling medium against steel ST 37 is done brinnel hardeness test using test equipment hardness tester. Of the 9 specimens lathe will be determined 3 points to do hardeness tests. From the result of hardness test and analysis obtained from hardness test on steel ST 37 average data that is use of soluble refrigerant media that produce a very good cooling at the time of the lathe process. The results of research is obtained that the use of soluble refrigerant media is the best with an average hardness of 224.10 kg / mm². On the lathe process, the cooling media has oil content will be able to maintain the scores hardness and time-worn on boring tool. Thus to maintain the hardness values can be used soluble oil cooling media and to increase the hardness values of workpieces can be used air cooling media.

A Contribution to the Mechanical Characterization of Cu ETP Used in the Electric Motors Industry

2012 ◽  
Vol 730-732 ◽  
pp. 679-684
Author(s):  
Pedro M.G.P. Moreira ◽  
Miguel A.V. de Figueiredo ◽  
Paulo M.S.T. de Castro
Keyword(s):  
Mechanical Characterization ◽  
Base Material ◽  
Tensile Tests ◽  
Electric Motors ◽  
Lower Strength ◽  
Before And After ◽  
Different Temperatures ◽  
Remote Stress ◽  
Hardness Values

The analysis of Cu ETP of a component of electric motors manufactured by WEG is presented. The work included three main tasks: metallographic analyses at the micro and macro levels; mechanical testing; scanning electron microscopy observations. The objective was the evaluation of the state of bars material before and after service. It was found that material in both conditions presents similar microstructures. This indicates that, despite the rotor working at temperatures above 300°C, no grain recrystallization can be identified. It was verified that the copper bar base material presents higher hardness values of than the copper ring. A decrease of yield and rupture stresses as the temperature increases was observed during tensile tests at different temperatures. During testing, a fatigue life of 107 cycles for a remote stress of approximately 134MPa is estimated. It can be concluded that the material after and before service presents different properties, the first one presenting lower strength. This behavior is reflected in lower hardness, yield and rupture stress of the material taken from the fractured rotor bars. This observation can be a result of the high temperature (above 300°C) that is present in the rotor during each start.

The Tensile Strength Effects on Precipitation Heat Treatment of 6061-T6 Aluminum Alloy

2009 ◽  
Author(s):  
CheeFai Tan ◽  
Md Radzai Said ◽  
Wei Chen
Keyword(s):  
Heat Treatment ◽  
Experimental Study ◽  
Aluminum Alloy ◽  
Room Temperature ◽  
Precipitation Hardening ◽  
Ageing Time ◽  
Hardness Test ◽  
Artificial Ageing ◽  
Before And After ◽  
Precipitation Heat

The paper presents an experimental study on precipitation of 6061-T6 aluminum alloy to determine the effects of artificial ageing on the effect of strength. The precipitation hardening usually undergoes a thermal treatment, which consists of a solution heat treatment (550°C for 1 hour), quenching (water, at room temperature) and artificial ageing. The experimental study is focused on artificial ageing upon which the temperature is varying between 175°C to 420°C at different period of time. The Vickers hardness test was carried out to evaluate the hardness before and after ageing. The optimum ageing time and temperature were also determined at the end of this experiment to obtain reductions in energy and total cost. The study leads to the conclusion that the optimum aged can be achieve within 175°C to 195°C with 2 to 6 hours of ageing time.

scholarly journals Characterization of Flexible Multi-Walled Carbon Nanotubes Network Sensor to Freon Gas Detection

2021 ◽  
pp. 2543-2554
Author(s):  
Nisreen M. Al-Makram ◽  
Wasan R. Saleh
Keyword(s):  
Room Temperature ◽  
Filter Cake ◽  
Operating Temperature ◽  
X Ray ◽  
Before And After ◽  
Recovery Times ◽  
Multi Walled Carbon Nanotubes ◽  
Response And Recovery ◽  
Walled Carbon Nanotubes

     MWCNTs-OH was used to prepare a flexible gas sensor by deposition as a network on a filter cake using the method of filtration from suspension (FFS). The morphological and structural properties of the MWCNTs network were characterized before and after exposure to Freon gas using FTIR spectra and X-ray diffractometer, which confirmed that the characteristics of the sensor did not change after exposure to the gas. The sensor was exposed to a pure Freon134a gas as well as to a mixture of Freon gas and air with different ratios at room temperature. The experiments showed that the sensor works at room temperature and the sensitivity values increased with increasing operating temperature, to be 58% until 150 ºC. The fabricated flexible sensor has good response and recovery times at low gas concentrations of 1.3, 2, and 2.7 ppm.

An Electron Microscope Study of Interdiffusion and Compound Formation in Ta-Au Thin Films

1973 ◽  
Vol 31 ◽  
pp. 32-33 ◽  
Author(s):  
T. C. Tisone ◽  
S. Lau
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Thermally Grown Oxide ◽  
Ion Milling ◽  
Compound Formation ◽  
Technology Application ◽  
Transmission Electron ◽  
Before And After ◽  
Au Thin Films

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.

Sign in / Sign up

Export Citation Format

Share Document