Improved Quality Truck Castings

2013 ◽  
Author(s):  
Kerry Jones
Keyword(s):  
Mechanical Properties ◽  
Data Analysis ◽  
Mechanical Testing ◽  
Fatigue Testing ◽  
Cast Steel ◽  
Charpy Impact ◽  
Component Failure ◽  
Independent Laboratory ◽  
Critical Areas ◽  
Current State

Component failure in bolsters and side frames remains a problem for both railroads and suppliers, causing expensive repairs and even derailments. To understand and combat this problem, an evaluation of the steel was required. Bolsters were obtained from several suppliers to evaluate the current state of Association of American Railroads (AAR) M-201 standard for Grade B+ cast steel. Charpy impact and tensile test samples were machined from critical areas of these castings and tested at an independent laboratory. Distinct differences were found in processes and in mechanical properties between some suppliers. Supplier names are not identified in this paper. Based on the chemical and mechanical testing results and data analysis, changes to AAR M-201 Grade B+ requirements have been proposed. Additional bolsters have been obtained for further testing. These bolsters will incorporate the proposed changes to the standard and the same mechanical testing will be performed on them to determine the effectiveness of the proposed changes. Full scale static or fatigue testing will be conducted on additional bolsters. A survey of scrapped bolsters and side frames from several railcar producers and reclaim operations was conducted to determine the leading causes of failures of components removed from service. These results form the basis for a database that can be used to identify failure trends.

Comparing fast inductive tempering and conventional tempering: Effects on microstructure and mechanical properties

2018 ◽  
Vol 115 (4) ◽  
pp. 407 ◽  
Author(s):  
Annika Eggbauer Vieweg ◽  
Gerald Ressel ◽  
Peter Raninger ◽  
Petri Prevedel ◽  
Stefan Marsoner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Charpy Impact ◽  
Heat Treating ◽  
Processing Route ◽  
High Heating Rate ◽  
Heating Rates ◽  
High Heating ◽  
Tempering Treatment ◽  
Carbide Distribution

Induction heating processes are of rising interest within the heat treating industry. Using inductive tempering, a lot of production time can be saved compared to a conventional tempering treatment. However, it is not completely understood how fast inductive processes influence the quenched and tempered microstructure and the corresponding mechanical properties. The aim of this work is to highlight differences between inductive and conventional tempering processes and to suggest a possible processing route which results in optimized microstructures, as well as desirable mechanical properties. Therefore, the present work evaluates the influencing factors of high heating rates to tempering temperatures on the microstructure as well as hardness and Charpy impact energy. To this end, after quenching a 50CrMo4 steel three different induction tempering processes are carried out and the resulting properties are subsequently compared to a conventional tempering process. The results indicate that notch impact energy raises with increasing heating rates to tempering when realizing the same hardness of the samples. The positive effect of high heating rate on toughness is traced back to smaller carbide sizes, as well as smaller carbide spacing and more uniform carbide distribution over the sample.

scholarly journals Current State and Challenges of Natural Fibre-Reinforced Polymer Composites as Feeder in FDM-Based 3D Printing

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2289
Author(s):  
Nishata Royan Rajendran Royan ◽  
Jie Sheng Leong ◽  
Wai Nam Chan ◽  
Jie Ren Tan ◽  
Zainon Sharmila Binti Shamsuddin
Keyword(s):  
Mechanical Properties ◽  
Natural Fibre ◽  
Critical Discussion ◽  
Fused Deposition Modelling ◽  
Preparation Methods ◽  
Fused Deposition ◽  
Current State ◽  
Future Challenges ◽  
Raster Angle ◽  
Fibre Reinforced Polymer

As one of the fastest-growing additive manufacturing (AM) technologies, fused deposition modelling (FDM) shows great potential in printing natural fibre-reinforced composites (NFRC). However, several challenges, such as low mechanical properties and difficulty in printing, need to be overcome. Therefore, the effort to improve the NFRC for use in AM has been accelerating in recent years. This review attempts to summarise the current approaches of using NFRC as a feeder for AM. The effects of fibre treatments, composite preparation methods and addition of compatibilizer agents were analysed and discussed. Additionally, current methods of producing feeders from NFRCs were reviewed and discussed. Mechanical property of printed part was also dependent on the printing parameters, and thus the effects of printing temperature, layer height, infill and raster angle were discussed, and the best parameters reported by other researchers were identified. Following that, an overview of the mechanical properties of these composites as reported by various researchers was provided. Next, the use of optimisation techniques for NFRCs was discussed and analysed. Lastly, the review provided a critical discussion on the overall topic, identified all research gaps present in the use of NFRC for AM processes, and to overcome future challenges.

scholarly journals Influence of a Natural Plant Antioxidant on the Ageing Process of Ethylene-norbornene Copolymer (Topas)

2021 ◽  
Vol 22 (8) ◽  
pp. 4018
Author(s):  
Anna Masek ◽  
Angelika Plota
Keyword(s):  
Mechanical Properties ◽  
Food Packaging ◽  
Colour Change ◽  
Good Alternative ◽  
Plant Origin ◽  
Aging Behavior ◽  
Current State ◽  
Ft Ir ◽  
Potential Use

In the field of polymer technology, a variety of mainly synthetic additives are used to stabilize the materials during processing. However, natural compounds of plant origin can be a green alternative to chemicals such as synthetic polyphenols. An analysis of the effect of hesperidin on the aging behavior of ethylene-norbornene copolymer was performed. The evaluation of changes in the tested samples was possible by applying the following tests: determination of the surface energy and OIT values, mechanical properties analysis, colour change measurements, FT-IR and TGA analyses. The obtained results proved that hesperidin can be effectively used as natural stabilizer for polymers. Furthermore, as a result of this compound addition to Topas-silica composites, their surface and physico-mechanical properties have been improved and the resistance to aging significantly increased. Additionally, hesperidin can act as a dye or colour indicator and only few scientific reports describe a possibility of using flavonoids to detect changes in products during their service life, e.g., in food packaging. In the available literature, there is no information about the potential use of hesperidin as a stabilizer for cycloolefin copolymers. Therefore, this approach may contribute not only to the current state of knowledge, but also presents an eco-friendly solution that can be a good alternative to synthetic stabilizers.

An Investigation of Mechanical Properties on Aluminium 6061 Reinforced with Silicon Carbide - Metal Matrix Composites

2015 ◽  
Vol 787 ◽  
pp. 568-572 ◽  
Author(s):  
A. Radha ◽  
K.R. Vijayakumar
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Metal Matrix ◽  
Charpy Impact ◽  
Vortex Method ◽  
Weight Fraction ◽  
Stir Casting ◽  
Matrix Composites ◽  
Casting Technique ◽  
High Fatigue

Composite materials like Aluminium metal matrix composite is playing a very important role in manufacturing industries e.g. automobile and aerospace industries, due to their superior properties such as light weight, low density, high specific modulus, high fatigue strength etc., In this study Aluminium(Al 6061) is reinforced with Silicon Carbide particles and fabricated by Stir Casting Technique (vortex method). The MMC rectangular bars (samples) are prepared with Al6061 and SiC (28 µ size) as the reinforced particles by weight fraction from 0%, 5%, 10%, and 15% of SiC. The microstructure analysis and Mechanical properties like Tensile Strength, Vickers Hardness and Charpy Impact Strength were investigated on prepared specimens. It is observed that the properties are increased with increasing of reinforced specimens by weight fraction.

scholarly journals Effect of Moisture Content on the Processing and Mechanical Properties of a Biodegradable Polyester

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1616
Author(s):  
Vincenzo Titone ◽  
Antonio Correnti ◽  
Francesco Paolo La Mantia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Moisture Content ◽  
Mechanical Testing ◽  
Hydrolytic Degradation ◽  
Slight Reduction ◽  
Biodegradable Polyester ◽  
Molding Process ◽  
Elongation At Break ◽  
Effect Of Moisture

This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing—causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens.

scholarly journals Mechanical Properties of an Igneous Aggregate-Modified Hydraulic Concrete

2001 ◽  
Vol 10 (2) ◽  
pp. 096369350101000
Author(s):  
E. Alonso ◽  
L. Martvnez-Gomez ◽  
W. Martvnez ◽  
L. Villaseρor ◽  
V.M. Castapo
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Testing ◽  
Mechanical Performance ◽  
Central Mexico ◽  
Natural Sources ◽  
Hydraulic Concrete ◽  
West Central ◽  
Careful Control

Portland cement concretes were prepared by adding different igneous materials from west central Mexico. The results of the mechanical testing of these materials show the feasibility of employing igneous minerals to produce concretes and mortars, provided a careful control of granulometry and the geochemistry involved is attained. The mechanical performance, as well as the workability of the slurries can be managed by the convenient use of commercial additives (i.e. water reducers and aging accelerators). These results open the attractive possibility of expanding the natural sources of concrete-forming elements.

Influence of Honeycomb Core Compression on the Mechanical Properties of the Sandwich Structure

2013 ◽  
Vol 486 ◽  
pp. 283-288
Author(s):  
Ladislav Fojtl ◽  
Soňa Rusnáková ◽  
Milan Žaludek
Keyword(s):  
Mechanical Properties ◽  
Impact Test ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Low Velocity Impact ◽  
Bending Test ◽  
Honeycomb Core ◽  
Low Velocity ◽  
Three Point Bending ◽  
Core Technology

This research paper deals with an investigation of the influence of honeycomb core compression on the mechanical properties of sandwich structures. These structures consist of prepreg facing layers and two different material types of honeycomb and are produced by modified compression molding called Crush-Core technology. Produced structures are mechanically tested in three-point bending test and subjected to low-velocity impact and Charpy impact test.

Computer-facilitated Qualitative Data Analysis: Potential Contributions to Management Research

1993 ◽  
Vol 19 (3) ◽  
pp. 637-660 ◽  
Author(s):  
Richard A. Wolfe ◽  
Robert P. Gephart ◽  
Thomas E. Johnson
Keyword(s):  
Data Analysis ◽  
Qualitative Data ◽  
Management Research ◽  
Qualitative Data Analysis ◽  
Current State ◽  
Management Literature ◽  
Software Programs ◽  
Effective Use

The development of software programs designed to facilitate qualitative data analysis has proltferated recently. Despite their potential to contribute much to management research, very little concerning the use of such programs has appeared in the management literature. The purpose of this paper is to review the current state of computer-facilitated qualitative data analysis [CQDA] in order to contribute to its effective use by management researchers. In an effort to achieve this purpose we discuss why CQDA programs are proliferating, describe the potential of such programs to contribute to management research, address program capabilities and features, describe CQDA applications in management research, and review issues researchers should be aware of in considering the use of C&DA.

Fatigue Life Improvement of Welded Elements and Structures by Ultrasonic Impact Treatment

2011 ◽  
Author(s):  
Yuriy Kudryavtsev ◽  
Jacob Kleiman
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Highway Bridges ◽  
Surface Layers ◽  
Ultrasonic Impact Treatment ◽  
Stress Relieving ◽  
Life Improvement

The ultrasonic impact treatment (UIT) is relatively new and promising process for fatigue life improvement of welded elements and structures. In most industrial applications this process is known as ultrasonic peening (UP). The beneficial effect of UIT/UP is achieved mainly by relieving of harmful tensile residual stresses and introducing of compressive residual stresses into surface layers of a material, decreasing of stress concentration in weld toe zones and enhancement of mechanical properties of the surface layers of the material. The UP technique is based on the combined effect of high frequency impacts of special strikers and ultrasonic oscillations in treated material. Fatigue testing of welded specimens showed that UP is the most efficient improvement treatment as compared with traditional techniques such as grinding, TIG-dressing, heat treatment, hammer peening and application of LTT electrodes. The developed computerized complex for UP was successfully applied for increasing the fatigue life and corrosion resistance of welded elements, elimination of distortions caused by welding and other technological processes, residual stress relieving, increasing of the hardness of the surface of materials. The UP could be effectively applied for fatigue life improvement during manufacturing, rehabilitation and repair of welded elements and structures. The areas/industries where the UP process was applied successfully include: Shipbuilding, Railway and Highway Bridges, Construction Equipment, Mining, Automotive, Aerospace. The results of fatigue testing of welded elements in as-welded condition and after application of UP are considered in this paper. It is shown that UP is the most effective and economic technique for increasing of fatigue strength of welded elements in materials of different strength. These results also show a strong tendency of increasing of fatigue strength of welded elements after application of UP with the increase in mechanical properties of the material used.

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