Experimental Study on the Crystallinity and Mechanical Properties of the Injection Molded Polypropylene

2011 ◽  
Vol 239-242 ◽  
pp. 2809-2812 ◽  
Author(s):  
Xiao Xun Zhang ◽  
Luo Wang ◽  
Qiu Hui Liao
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Diffraction Method ◽  
Processing Conditions ◽  
Mould Temperature ◽  
X Ray Diffraction ◽  
Melt Temperature ◽  
X Ray ◽  
Injection Speed ◽  
Injection Molded

Polypropylene specimens were made by the injection molding experiments under different processing conditions. The crystallinity of each polypropylene specimen was obtained using the X-ray diffraction method. The effects of the injection molding processes on the crystallinity of polypropylene were revealed: (1) the crystallinity decreases as the melt temperature increases, and the higher the melt temperature, the slower the crystallinity decreases, (2) the crystallinity decreases as the mould temperature increases, and the higher the mould temperature, the faster the crystallinity decreases, (3) the crystallinity increases as the injection speed increases, and the larger the injection speed, the faster the crystallinity increases. By the tensile experiments of the injection molded specimens, it is also found that the crystallinity has a major impact on the mechanical properties of polypropylene. The yield strength and tensile strength of polypropylene specimens increase as the crystallinity increases.

X-ray diffraction studies of rapid cooled Al-V and Al-Fe-V alloys

2019 ◽  
Vol 1 (96 extended issue) ◽  
pp. 5-11
Author(s):  
O. Shved ◽  
S. Mudry ◽  
V. Girzhon ◽  
O. Smolyakov
Keyword(s):  
Mechanical Properties ◽  
Physical Properties ◽  
Amorphous Matrix ◽  
Diffraction Method ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Rapid Cooling ◽  
X Ray ◽  
Cell Parameters ◽  
Nonequilibrium Conditions

Purpose: of this paper is to deep and more complete knowledge about the features of phase and structure formation in Al-based alloys with transition metals (TM) Fe and V at rapid cooling from melt. It is known, that nonequilibrium synthesis conditions of such alloys lead to quasicrystalline, amorphous or metastable phases formation, which can significantly improve the physical-chemical properties and first of all the mechanical ones. But understanding of compositional dependences of structure features at formation under nonequilibrium conditions and the correlation of these dependences with physical properties of alloys is far to be clear. Design/methodology/approach: Structure of Al-enriched Al-V, Al-V-Fe rapid cooled alloys was studied by X-ray diffraction method. In order to estimate the influence of structural state of alloy on the mechanical properties the integral microhardness was studied by Vickers method. Findings: Two quasicrystalline icosaedral phases with different cell parameters are revealed in ternary alloys Al100-3xV2xFex (x=2-4). Increasing of transition metal content promotes the formation of phase with higher quasicell parameter embedded in amorphous matrix. With increasing of the transition elements total content from 6 up to 12 at. % the microhardness of alloys increased gradually from 867 to 3050 MPa. Research limitations/implications: Research of nonequilibrium alloys revealed crystalline structure of Al-V alloys and quasicrystalline embedded in amorphous matrix of Al-Fe-V ternary alloys. Obtained results suppose that further structure and physical properties studies of Al-Fe-V alloys will allows to find the conditions to control the producing of materials with desired properties. Practical implications: Using of rapid cooling method for synthesis of Al-enriched Al-Fe-V alloys give an opportunity to produce alloys with significantly improved mechanical properties. Originality/value: Nonequilibrium conditions of cooling allow significantly changes the structure and properties.

Effect of Processing Conditions on Properties of KMnO4-Treated PAN Fibers

2013 ◽  
Vol 821-822 ◽  
pp. 23-27
Author(s):  
Xiang Li ◽  
Chun Yi Liu ◽  
Ai Wen Qin ◽  
Xin Zhen Zhao ◽  
Chun Ju He
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Chemical Structure ◽  
Suitable Condition ◽  
Wide Angle ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Pan Fibers

Plasticized polyacrylonitrile(PAN) fibers have been chemically impregnated with aqueous solution of KMnO4under varying conditions of temperature and time. The effect of modification conditions on the chemical structure and the mechanical properties of precursor fibers are characterized by wide-angle X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. The experimental results show that KMnO4can be used not only as catalyst for cyclization reaction, but also as plasticizer. The chemical modification between KMnO4and PAN can not occur below70°C, the most suitable condition for modification is performed at 80°C for 5 min.

Influence of Injection and Cavity Pressure on the Demoulding Force in Micro-Injection Moulding

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
C. A. Griffiths ◽  
S. S. Dimov ◽  
S. G. Scholz ◽  
G. Tosello ◽  
A. Rees
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Design Of Experiment ◽  
Injection Moulding ◽  
Processing Conditions ◽  
Cavity Pressure ◽  
Mould Temperature ◽  
Melt Temperature ◽  
Injection Speed ◽  
Micro Injection Moulding

The paper reports an experimental study that investigates part demoulding behavior in micro-injection moulding with a focus on the effects of pressure and temperature on the demoulding forces. In particular, the demoulding performance of a representative microfluidics part was studied as a function of four process parameters, melt temperature, mould temperature, holding pressure, and injection speed, employing the design of experiment approach. In addition, the results obtained using different combinations of process parameters were analyzed to identify the best processing conditions in regards to demoulding behavior of microparts when utilizing a COC polymer to mould them.

Measurement of Alloying Degree of Galvannealed Steels by X-Ray Diffraction

2006 ◽  
Vol 321-323 ◽  
pp. 1461-1464 ◽  
Author(s):  
Hyoung Kuk Park ◽  
Jea Hwa Hong ◽  
Chong Soo Lee
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Quantitative Analysis ◽  
Xrd Analysis ◽  
Pls Regression ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Excellent Corrosion Resistance ◽  
Galvannealed Steel

Galvannealed steels are produced by reheating of Zinc-coated steels, in which the iron and the zinc are interdiffused to form Zn-Fe intermatallic compound. In recent years, application of galvannealed steel has increased due to its excellent corrosion resistance, good weldability and paintability. Galvannealed production requires strict control of processing conditions to obtain an optimal alloying degree in the coatings. The analysis of the alloying degree is very important since they are closely related to the corrosion and mechanical properties. This study is measurement of alloying degree of the galvannealed steel by using the XRD. Partial least squares (PLS) model is a powerful multivariate tool that has been successfully applied to the quantitative analysis of data in XRD. The alloying degree was determined by using PLS regression to a concentration accuracy of 0.2%. The XRD analysis and proposed PLS model can be successfully used to determine the alloying degree of industrially produced galvannealed steel.

Stereocomplex formation in injection-molded poly(L-lactic acid)/poly(D-lactic acid) blends

2019 ◽  
Vol 39 (3) ◽  
pp. 279-286
Author(s):  
Yottha Srithep ◽  
Dutchanee Pholhan ◽  
Lih-Sheng Turng ◽  
Thiptida Akkaprasa
Keyword(s):  
Lactic Acid ◽  
Injection Molding ◽  
Melting Peak ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Neat Plla ◽  
Stereocomplex Formation ◽  
Injection Molded ◽  
Complex Crystal

AbstractPoly(L-lactic acid)/poly(D-lactic acid) (PLLA/PDLA) blends were prepared by hand mixing, followed by injection molding at 210°C to produce tensile specimens. Thermal properties, crystalline structure, and mechanical properties were measured by differential scanning calorimetry (DSC), thermogravimetric analysis, wide-angle X-ray diffraction (XRD), and tensile testing. From the DSC tests of blends ranging from 10% to 30% PDLA in PLLA, the PDLA melting peak was absent and was replaced by a stereocomplex melting peak at 210°C, which was ~50°C higher than that for neat PLLA or PDLA. The reverse blending of PLLA into PDLA showed a similar behavior. Surprisingly, three melting peaks (for PLLA, PDLA, and the complex crystal) appeared in the 1:1 PLLA:PDLA pellet blends. However, the PLLA and PDLA powders (ground to less than 200 μm) and hand mixed, prior to injection molding, showed only small amounts of homocrystals and much higher fractions of stereocomplex crystals (18–44%). Compared to the hand mixed un-ground pellets, molded specimens from the PLLA and PDLA powders also exhibited higher tensile strengths (33–48 MPa) and moduli (1100–1250 MPa). Moreover, the stereocomplex formation was found to enhance the thermal stability compared with those of the pure PLLA and PDLA.

scholarly journals Influence of Compatibilizer and Processing Conditions on Morphology, Mechanical Properties, and Deformation Mechanism of PP/Clay Nanocomposite

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
B. Akbari ◽  
R. Bagheri
Keyword(s):  
Mechanical Properties ◽  
Deformation Mechanism ◽  
Feeding Rate ◽  
Processing Conditions ◽  
Feeding System ◽  
Rotor Speed ◽  
X Ray Diffraction ◽  
Screw Extruder ◽  
X Ray ◽  
Twin Screw

Polypropylene/montmorillonite nanocomposite was prepared by melt intercalation method using a twin-screw extruder with starve feeding system in this paper. The effects of compatibilizer, extruder rotor speed and feeding rate on properties of nanocomposite were investigated. Structure, tensile, and impact properties and deformation mechanism of the compounds were studied. For investigation of structure and deformation mechanisms, X-ray diffraction (XRD) and transmission optical microscopy (TOM) techniques were utilized, respectively. The results illustrate that introduction of the compatibilizer and also variation of the processing conditions affect structure and mechanical properties of nanocomposite.

Correlation Between Mechanical Properties in Standard Test Specimens and Injection Molded Thin-Wall Parts

2013 ◽  
Author(s):  
Laurentiu I. Sandu ◽  
Felicia Stan ◽  
Catalin Fetecau
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Yield Strength ◽  
Injection Molding ◽  
Process Conditions ◽  
Thin Wall ◽  
Optimal Process ◽  
Melt Temperature ◽  
Molded Parts ◽  
Injection Molded

In this paper, we investigated the effect of injection molding parameters on the mechanical properties of thin-wall injection molded parts. A four-factor (melt temperature, mold temperature, injection speed and packing pressure) and three-level fractional experimental design was performed to investigate the influence of each factor on the mechanical properties and determine the optimal process conditions that maximize the mechanical properties of the part using the signal-to-noise (S/N) ratio response. The mechanical properties (e.g., elastic modulus, yield strength and strain at break) were measured by tensile tests at room temperature, at a crosshead speed of 5 mm/min, and compared with those of the injection-molded specimens. The experimental results showed that the tensile properties were highly dependent on the injection molding parameters, regardless of the type of the specimens. The values of Young modulus and yield strength of the injection-molded specimens were lower than those of the injection-molded parts, while the elongation at break was considerably lower for the injection-molded parts. The optimal process conditions were strongly dependent on the measured performance quantities (elastic modulus, yield strength and strain at break).

Transient Liquid Phase Bonding of Alumina to Alumina via Bismuth Oxide Interlayer

2013 ◽  
Vol 829 ◽  
pp. 136-140
Author(s):  
Omid Bahman Dehkordi ◽  
Ali Mohamad Hadian
Keyword(s):  
Mechanical Properties ◽  
Liquid Phase ◽  
Cross Section ◽  
Bismuth Oxide ◽  
Transient Liquid Phase ◽  
Diffraction Method ◽  
Transient Liquid Phase Bonding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Testing Method

Bismuth oxide, due to its low melting point was selected as filler for joining alumina to alumina using Transient Liquid Phase (TLP) method. For this purpose a thin layer of bismuth oxide was placed as an interlayer between the ceramic bodies. To study the effect of time and temperature on the mechanical properties of the joined samples, the joining tests were carried out in 900, 1000 and 1100°C for various times. The mechanical properties of the joined samples were measured using shear testing method. To investigate the microstructure of the joining area, the cross section ofthe joints were studied using scanning electron microscope (SEM) and X-ray diffraction method. The results showed that longer joining times results in higher mechanical properties of the joints. The highest joint strength of about 80 MPa was obtained for the sample joined in 900°C for 10hour.

Effects of Gate Locations on the Tensile Strength of Injection Molded Weld Lines

2013 ◽  
Vol 561 ◽  
pp. 64-69
Author(s):  
Yu Mei Ding ◽  
Xiao Hua Wang ◽  
Peng Cheng Xie ◽  
You Chen Zhang ◽  
Wei Min Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Mechanical Test ◽  
Injection Pressure ◽  
Melt Temperature ◽  
Injection Speed ◽  
Appearance Quality ◽  
Study Results ◽  
Molded Parts ◽  
Injection Molded

As unfavorable molding defect, weld lines often result in reduced mechanical properties and poor appearance quality of injection molded parts. In this present work, effects of gate locations on the tensile strength of weld lines were investigated by changing the distances between two gates in 10mm, 20mm and 25mm, respectively. Test specimens were prepared with an all-electrical injection molding machine under different process parameters (injection speed, injection pressure and melt temperature). Visualization method and scanning electron microscope (SEM) were employed to further discuss mechanical test results. Study results indicated that tensile strength of injection molded weld lines was lessened as the increase of gate distances. Higher injection speed, higher injection pressure and lower melt temperature induced to lower weldline tensile strength whatever the gate locations were. Study results also illustrated that it was gate location rather than molding conditions had the most decisive influence on the weldline mechanical properties.

scholarly journals Investigation of Icrostructure, Mechanical and Temperature Effects on Biomedical Co-25Cr-9,5W-3,5Mo-1Si Alloys Fabricated by Additive Manufacturing

2019 ◽  
Author(s):  
Ebuzer aygul ◽  
senai yalcinkaya ◽  
yusuf sahin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Electrochemical Corrosion ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manufacturing Method ◽  
Wear And Corrosion ◽  
Wear And Corrosion Resistance ◽  
Secondary Annealing

The Wolfram (W), Silicium (Si) and Molybdenum (Mo) doped Co-Cr biomedical alloy were fabricated by additive manufacturing method, which is part of powder metadology. The mixture of Wolfram (W), Silicium (Si), Chrome (Cr) and Cobalt (Co) alloy is known good wear and corrosion resistance among of biomedical applications. By addition of Molybdenum (Mo) into the structure of alloy, the structure become more stbale also increase the corrosion and wear resistance. In addition, the effects of secondary annealing process on the alloy were investigated. The microstructure of the produced alloy was analyzed by X-ray diffraction method XRD, Energy Dispersive X-Ray Analysis EDX and scanning electron microscope SEM. Moreover, Electrochemical corrosion test, micro hardness and density measurements were performed to investigate the mechanical properties of the alloy. As a result of the analyzes, the effects of Molydenum (Mo) doped and secondary annealing on the microstructure and mechanical properties of bioalloying were determined.

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