Effects of the Microstructure and Mechanical Properties for Wear Resistant Casting Surface with Vacuum Evaporable Pattern Casting Infiltration Process

2011 ◽  
Vol 291-294 ◽  
pp. 176-179
Author(s):  
Da Chun Yang

Wear-resistant casting was made by V-EPC infiltration process. The matrix material was high boron steel casting. Surface composite materials layer was ceramic particles, such as WC, Ferrochromium, and Borax, etc. High boron molten metal was infiltrated into the composite layer and a good cast-infiltration layer may be formed by the interaction of vacuum and high temperature. The wear-resistant casting made with this process has high strength, hardness, and good wear-resistance. It is a new process that wear-resistant casting will be made of.

2012 ◽  
Vol 538-541 ◽  
pp. 247-250
Author(s):  
Da Chun Yang

Wear-resistant casting was made by V-EPC infiltration process. This paper puts forward and analyses the mechanical properties and forming mechanism of the layer. The matrix material was high boron steel casting. By partial casting alloyed, the surface composite materials layer was ceramic particles, such as WC, Ferrochromium, and Borax, etc. High boron molten metal was infiltrated into the composite layer and a good cast-infiltration layer may be formed by the interaction of vacuum and high temperature. The test result shows that using this process we can get the casting surface which is special abrasion-resistance with the remarkable characteristics such as simple process and low cost. It is a new process that wear-resistant casting will be made of.


2015 ◽  
Vol 766-767 ◽  
pp. 252-256 ◽  
Author(s):  
A. Siddique Ahmed Ghias ◽  
B. Vijaya Ramnath

The composite material is a combination of two or more materials with different physical and chemical properties. The composite has superior characteristics than those individual components. A hybrid composite is the one which contains at least three materials. When the matrix material is a metal, the composite is termed as metal matrix composites (MMC). The MMC is a composite material with two constituent parts, one being a metal. The other material may be another metal, ceramic or fiber. Among all the MMC’s, Aluminium is the most widely used matrix material due to its light weight, high strength and hardness. This paper deals with the fabrication and mechanical investigation of hybrid metal matrix composite Al - SiC. The fabrication is done by stir casting by adding the required quantities of additives into the stirred molten Aluminium. The results show significant effect of mechanical properties such as tensile strength, yield stress and flexural strength. The internal structure of the composite is observed using Scanning electron microscope (SEM) and found that are formation of pores in them.


2020 ◽  
Vol 4 (2) ◽  
pp. 115-126
Author(s):  
Anil K. Matta ◽  
Naga S. S. Koka ◽  
Sameer K. Devarakonda

Magnesium Metal Matrix Composites (Mg MMC) have been the focus of consideration by many researchers for the past few years. Many applications of Mg MMCs were evolved in less span of time in the automotive and aerospace sector to capture the benefit of high strength to weight ratio along with improved corrosion resistance. However, the performance of these materials in critical conditions is significantly influenced by several factors including the fabrication methods used for processing the composites. Most of the papers addressed all the manufacturing strategies of Mg MMC but no paper was recognized as a dedicated source for magnesium composites prepared through stir casting process. Since stir casting is the least expensive and most common process in the preparation of composites, this paper reviews particulate based Mg MMCs fabricated with stir casting technology. AZ91 series alloys are considered as the matrix material while the effect of different particle reinforcements, sizes , weight fractions on mechanical and tribological responses are elaborated in support with micro structural examinations. Technical difficulties and latest innovations happened during the last decade in making Mg MMCs as high performance material are also presented.


Author(s):  
Fabrizia Ghezzo ◽  
Xi Geng Miao

Lightweight, high strength fibre-reinforced polymeric composites are leading materials in many advanced applications including biomedical components. These materials offer the feasibility to incorporate multi functionalities due to their internal architecture, heterogeneity of materials and the flexibility of combining them using currently available fabrication methods. In spite of the excellent properties of these materials, their failure is still a questionable and not well predicted event. Delamination, debonding and micro-cracks are only some of the failure mechanisms that affect the matrices of polymer based composites. More complex cases exist with the combination of multiple failure mechanisms. In such cases a self-repairing mechanism that can be auto-triggered in the matrix material once the crack has been formed, would be very beneficial for all the applications of these materials, reducing maintenance costs and increasing their safety and reliability. Self-healing materials have been studied for more than a decade by now, with the specific objective of reducing the risks and costs of cracking and damage in a wide range of materials. Different approaches have been taken to create such materials, depending on the kind of material that needs to be repaired. The most popular methods developed for polymers and polymer reinforced composites are considered in this review. These methods include materials with micro-capsules containing a healing agent, and composites with matrices that can self-heal the cracks by repairing the broken molecular links upon external heating. While the first approach to healing has been widely used and studied in the past decade, in this review we focus on the second approach since less is reported in the literature and more difficult is the development of the materials based on such a method.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 407
Author(s):  
Eulalia Gliscinska ◽  
Javier Perez de Amezaga ◽  
Marina Michalak ◽  
Izabella Krucinska

This article presents thermoplastic sound-absorbing composites manufactured on the basis of renewable raw materials. Both the reinforcing material and the matrix material were biodegradable and used in the form of fibers. In order to mix flax fibers with polylactide fibers, the fleece was fabricated with a mechanical system and then needle-punched. The sound absorption of composites obtained from a multilayer structure of nonwovens pressed at different conditions was investigated. The sound absorption coefficient in the frequency ranging from 500 Hz to 6400 Hz was determined using a Kundt tube. The tests were performed for flat composites with various structures, profiled composites, and composite/pre-pressed nonwoven systems. Profiling the composite plate by convexity/concavity has a positive effect on its sound absorption. It is also important to arrange the plate with the appropriate structure for the incident sound wave. For the composite layer with an added pre-pressed nonwoven layer, a greater increase in sound absorption occurs for the system when a rigid composite layer is located on the side of the incident sound wave. The addition of successive nonwoven layers not only increases the absorption but also extends the maximum absorption range from the highest frequencies towards the lower frequencies.


Author(s):  
R.C. Burghardt ◽  
J.M. Ehrman ◽  
T.C. Stephens ◽  
M.F. Hibbs

Graphite fiber-reinforced resin composite materials have a wide use in aerospace, automotive and sporting goods applications where high strength to weight ratios are requisite. Many of these materials use highly cross-linked epoxy resins as the matrix material. Unfortunately these resins have a low resistance to crack propagation and as a result research efforts have been directed towards reducing this tendency.The ability to measure microscopic displacements and calculate strain fields in the vicinity of a fracture crack tip under experimental conditions was needed in order to help predict the fracture resistance of various composite materials being tested. A technique was developed that made it possible to derive displacement measurements on a micrometer scale in the region of a crack tip from observations of epoxy-based composites being fractured using a tensile stage equipped scanning electron microscope (SEM). Samples were polished on the surface to be observed and sputter coated with 5 to 10 nanometers of either gold or 60:40 gold-palladium prior to mounting on the TS-2 tensile stage of a JEOL JSM-35CF. This instrument was also equipped with a Krisel beam interceptor, a beam current meter, a Tracor Northern TN-2000 x-ray analyzer and a TN-1310 digital beam control system. Using the digital beam and x-ray mapping capabilities a matrix of small dots was “written” onto the surface of the sample as shown in figure 1.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 524 ◽  
Author(s):  
Sergey V. Panin ◽  
Boris A. Lyukshin ◽  
Svetlana A. Bochkareva ◽  
Lyudmila A. Kornienko ◽  
Duc Ahn Nguyen ◽  
...  

The main goal of this paper is to design and justify optimized compositions of thermoplastic–matrix wear-resistant composites based on polyetheretherketone (PEEK) and polyphenylene sulfide (PPS). Their mechanical and tribological properties have been specified in the form of bilateral and unilateral limits. For this purpose, a material design methodology has been developed. It has enabled to determine the optimal degrees of filling of the PEEK- and PPS-based composites with carbon microfibers and polytetrafluoroethylene particles. According to the results of tribological tests, the PEEK-based composites have been less damaged on the metal counterpart than the PPS-based samples having the same degree of filling. Most likely, this was due to more uniform permolecular structure and greater elasticity of the matrix. The described methodology is versatile and can be used to design various composites. Its implementation does not impose any limits on the specified properties of the material matrix or the reinforcing inclusions. The initial data on the operational characteristics can be obtained experimentally or numerically. The methodology enables to design the high-strength wear-resistant composites which are able to efficiently operate both in metal–polymer and ceramic–polymer friction units.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Eugene Kim ◽  
Xuyan Qin ◽  
James B. Qiao ◽  
Qingqing Zeng ◽  
John D. Fortner ◽  
...  

Abstract Graphene oxide (GO)-based composite materials have become widely popular in many applications due to the attractive properties of GO, such as high strength and high electrical conductivity at the nanoscale. Most current GO composites use organic polymer as the matrix material and thus, their synthesis suffers from the use of organic solvents or surfactants, which raise environmental and energy-consumption concerns. Inspired by mussel foot proteins (Mfp) secreted by the saltwater mussel, Mytilus galloprovincialis and by recent advances in microbial protein production, we developed an aqueous-based green synthesis strategy for preparing GO/Mfp film composites. These GO/Mfp films display high tensile strength (134–158 MPa), stretchability (~ 26% elongation), and high toughness (20–24 MJ/m3), beyond the capabilities of many existing GO composites. Renewable production of Mfp proteins and the facile fabrication process described provides a new avenue for composite material synthesis, while the unique combination of mechanical properties of GO/Mfp films will be attractive for a range of applications.


Whiskers and high-strength filaments as potential reinforcing materials differ in their proper­ties. Their applicability in fibre-reinforced composites depends on these properties. The short­ness of the whiskers, the large scatter of their strength and their high price involve difficulties for their use in composites. The more advantageous geometry of continuously produced filaments, their relatively low price and their good processing qualities favour the use of quasi-endless filaments as reinforcing material. The latter holds especially for the production of rotationally symmetric shaped parts, where the 'filament-winding technique' is applied. But even parts which are not rotationally symmetric can be produced by this technique if it is used as an intermediate stage of shaping. This method has been applied to produce filament-reinforced shaped parts with plastics, light-metal, heavy-metal and glass matrices. As filamentary reinforcing materials fine steel wire is preferably used; some others are produced by the improved Taylor method. The strength values measured on the composites amount to a multiple of the strength of the matrix material and are in satisfactory agreement with theory.


2010 ◽  
Vol 636-637 ◽  
pp. 260-265 ◽  
Author(s):  
José M. Silva ◽  
Tessaleno C. Devezas ◽  
A. Silva ◽  
L. Gil ◽  
C. Nunes ◽  
...  

Aerospace components are characterized by having high strength to weight ratios in order to obtain lightweight structures. Recently, different types of sandwich components using composite materials have been developed with the purpose of combining the effect of reinforced face-sheets with low weight core materials, such as honeycombs and foams. However, these materials must combine damage tolerance characteristics with high resistance under both static and dynamic loads. Cork composites can be considered as an alternative material for sandwich components since cork is a natural material with some remarkable properties, such as high damage tolerance to impact loads, good thermal and acoustic insulation capacities and excellent damping characteristics for the suppression of vibrations. The experiments carried out in this investigation were oriented in order to optimize the specific strength of cork based composites for sandwich components. Static bending tests were performed in order to characterize the mechanical strength of different types of cork agglomerates which were obtained considering distinct production variables. The ability to withstand dynamic loads was also evaluated from a set of impact tests using carbon-cork sandwich specimens. The results from experimental tests showed that cork agglomerates performance depends on the cork granulate size, the type of reinforcing elements and the bonding procedure used for the cohesion with the matrix material.


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