Charaterization and Preparation of PA6/EPDM-g-MAH/OMMT Polymer Alloys Nanocomposites

The Polyamide 6 (PA6)/ maleic anhydride grafted ethylene-propylene-diene monomer (EPDM-g-MAH)/organic montmorillonite (OMMT) nanocomposites were successfully prepared by melt extrusion method at different contents of OMMT fillers. The content of OMMT were studied to discuss the mechanical properties, thermal resistance properties and melt-crystal behavior of the nanocomposites. The results were summarized as follows: The PA6/EPDM-g-MAH/OMMT nanocomposites were prepared using melt extrusion method. The influence of the OMMT filler contents on the properties of PA6/EPDM-g-MAH/OMMT nanocomposites were studied. The mechanical properties and thermal resistance properties were improved with the addition of OMMT. The results showed that when the content of OMMT was 3.5wt%, comparing to the pure PA6, the bending strength was improved 31.7%, the notch impact strength was improved by 40.5%, and the heat deflection temperature was improved by 31.1°C. This kind of nanocomposites had good application prospects.

The Study Toughness Ecologicals Metals Materials

This aim of this is to determine the manner of realizing tubing pipe, which have to comply with suplimentary requirements concerning the notch impact strength at lower temperature (below - 300C). We realized �73 x 5.51 mm and �89 x 13 mm pipes applying various final heat treatment variants. For each heat treatment variant were determined the mechanical properties and the impact absorbed energy at temperatures between (-60 0C and +15 0C).

The Spread of Corrosion in Cast Iron and its Effect on the Life Cycle of Transportation Vehicles

This article deals with the spread of corrosion in material at different exposure times, and its effect on the measured brittle fracture and notch impact strength under different temperature conditions. To assess the degradational effect of corrosion on the material characteristics represented by the measured impact strength, we conducted a fractographic analysis of fracture surfaces, the aim of which was to evaluate the spread of corrosion in the material. In the first part of the experiment, two corrosion tests are simulated with a duration time of 432 and 648 hours, to compare the degradation effect of corrosion on the notch impact strength, depending on the duration of the corrosion tests. The following part shows the results of the impact bending test, where the experiment was conducted in an area of reduced and increased temperatures. The final part summarizes the results of the fractographic analysis of sample fracture surfaces from the impact bending tests. Based on the measured the length of the corrosion cracks, we analyzed the sample at the notch and from the material surface after the impact bending test.

Hot Isostatic Pressing of a Varying Thickness, Thick-Walled Vessel (Reactor Circulating Pump Bowl) for a Pressurised Water Reactor (PWR) Application

This paper presents an overview of the work undertaken by Rolls-Royce to justify the use of a Hot Isostatically Pressed (HIP) Reactor Circulating Pump (RCP) bowl manufactured in 316L stainless steel for a Pressurised Water Reactor (PWR) application. It presents the work from a design justification/manufacturing quality assurance perspective, rather than from a pure metallurgical perspective. Although the HIP process is not new, it was new in its application to Rolls-Royce designed nuclear reactor plant. As a consequence, Rolls-Royce has implemented an evolving, staged approach, starting with HIP bonding of solid valve seats into small bore valve pressure boundaries. This was followed by powder HIP consolidation of leak-limited, thin-walled toroids, and has culminated in the powder HIP consolidation of thick-walled components such as RCP bowls. The paper provides an overview of each of these stages, the method of manufacture for the RCP bowl, and the approach taken with respect to justification. In previous Rolls-Royce applications of HIP to PWR plant components, the component section thickness has been fairly consistent. For the RCP bowl application, the section thickness varies quite considerably. To assess any variation in properties as a result of section thickness variation, a stepped wedge technology demonstrator was first manufactured and non-destructively and destructively examined to assess whether material properties remain within specification. The paper presents material property results for ‘Near Surface’ and ‘Buried’ samples taken from section thicknesses covering 50mm to 300mm. Yield, Ultimate Tensile Strength (UTS), Charpy ‘V’ notch impact strength and Strauss test results were found to be within specification for all section thicknesses. An analysis of the data shows no statistical difference in material properties across the different section thicknesses for both near surface and buried properties, except for Charpy ‘V’ notch impact strength, for which, above 50mm, mean ‘Buried’ strength is significantly higher than mean strength for ‘Near Surface’. It is observed that the mean ‘Near Surface’ yield and tensile strength appears to increase with section thickness; however, there are insufficient data to demonstrate whether or not the increase is statistically significant. There appears to be a reduction in mean ‘Buried’ yield strength when the section thickness is at 300mm, compared to thinner sections, but again, the current data are insufficient to determine whether or not the reduction is statistically significant. It could be postulated that there is a point at which the section thickness starts to influence the cooling rate, and as a consequence grain growth may be more prominent at the ‘Buried’ position. This could result in yield and tensile material properties being detrimentally affected. However, this is not supported by an analysis of Charpy ‘V’ notch impact strength results, for which a similar reduction would be expected; the highest ‘Buried’ Charpy results occur in the thickest section. Further work is ongoing to understand this observation. Non-destructive examination results of a prototype RCP bowl are presented. This shows no defects identified from dye penetrant surface examination and ultrasonic testing for a rejection level set at a 3mm flat bottomed hole.

Changes of Mechanical Properties in Response to Changes in the Microstructure of High Pressure Steel Cylinders Obtained by the Various Heat Treatments

The field of high-pressure steel cylinders (HPSC) and vessels used for the variety of applications especially for the CNG (Compressed Natural Gas) in automotive industry is still expanding. With increasing safety requirements, a need of new techniques applied in field of HPSC structural innovations comes into place. Conventional treatment provides generally sufficient parameters of HPSC, but the long-term goal is to achieve as high as possible strength properties vs. as high as possible notch impact strength, which is currently difficult fully accessible, because of the banded structures (segregation banding) created during the process of reversed extrusion and reversed hot rolling.

Toughening Modification of PA6 with Different Core-Shell Particles

(POE-g-MAH/OMMT) and (POE-g-MAH/SiO2) toughening particles of core-shell structure were prepared by ball grinding method and were used to modify toughness of PA6.The morphology of PA6 modified by these core-shell particles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM),and were detected by mechanical performance test. The results show that both toughening particles could improved notch impact strength of PA6,and with toughening particle exceed 10%, composites notch impact strength is rapid increase.(POE-g-MAH/OMMT) particle of PA6 toughening effect is better than (POE-g-MAH/SiO2).When material under impact, OMMT produced slip effect in core-shell structure and SiO2 produced rolling effect.

Study on Non-Halogen Flame-Retarded HIPS with High Strength HIPS

PPO was a better intensifier and charred material for High-impact polystyrene (HIPS), it could make HIPS achieve UL94V-0 with APP, MC, RDP. Especially, RDP not only improved the flame-retarded property but also controlled the hole producing, and had the best consistent with matrix which could improve the mechanical properties. SBS and SEBS were better consistent with matrix, especially SEBS was tiny granule, which could be dispersed in matrix easily. The properties of SEBS toughened the non-halogen flame-retarded HIPS was followed: tensile strength: 18.83MPa; izod notch impact strength: 15.7kJ/m2; UL94V-0.

Reactive Compatibilization in Nano-Silica Filled Polypropylene Composites

Nano-sized silica was pre-grafted with poly(glycidyl methacrylate) (PGMA) by solution free-radical polymerization. When these grafted silica particles were melt compounded with polypropylene (PP), reactive compatibilization effect was perceived due to the chemical bonding between the PGMA and amine functionalized PP, which led to a significant increase of tensile strength and notch impact strength of PP at rather low filler content. Accordingly, compatibility of each kind of the functionalized PP with grafted SiO2 was evaluated through investigating the mechanical properties, crystallization behavior and rheological performance of the composites. The results show that the reactive compatibilization is capable of providing stronger interfacial adhesion.

Preparation of Nano-Silica/Polypropylene Composites Using Reactive Compatibilization

Nano-sized silica particles were pre-grafted with poly(glycidyl methacrylate) (PGMA) by solution free-radical polymerization. When these grafted silica nanoparticles were melt compounded with polypropylene (PP), reactive compatibilization effect was perceived due to the chemical bonding between the grafted PGMA and amine functionalized PP, which led to a significant increase of tensile strength and notch impact strength of PP at rather low filler content. Accordingly, compatibility of each kind of the functionalized PP with grafted SiO2 nanoparticles was evaluated through investigating the mechanical properties, crystallization behavior and rheological performance of the composites. The results show that the reactive compatibilization is capable of providing stronger interfacial adhesion.