Temat: micro-hardness - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: On the Load Dependence of Micro-Hardness Measurements: Analysis of Data by Different Models and Evaluation of Measurement Errors
Autorzy:: Petrik, J.
Tematy:: micro-hardness
ISE
standard reference block; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/353270.pdf Link otwiera się w nowym oknie
Opis:: The influence of applied loads between 0.09807 N and 0.9807 N on measured values of micro-hardness was evaluated by Meyer’s index n, proportional specimen resistance model (PSR) and Hays – Kendall methods, Total Dispersion Zone and Analysis of Variance (ANOVA). The measurement was repeated 6 times using the same hardness reference block with standard hardness H_c = 327 HV0.05 as a sample. The influence of the load on the measured value of micro-hardness is statistically significant, and the relationship between applied load and micro-hardness manifests reverse indentation size effect (ISE) for most of “measurements”. The high value of the uncertainty of results can affect the existence and nature of ISE, especially at low loads.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: “In-vitro” Tests on New Biodegradable Metallic Material Based on ZnMgY
Autorzy:: Panaghie, Catalin
Cimpoesu, Nicanor
Benchea, Marcelin
Roman, Ana-Maria
Manole, Vasile
Alexandru, Adrian
Cimpoesu, Ramona
Cazacu, Marius Mihai
Wnuk, Izabela
Zegan, Georgeta
Tematy:: biodegradable
tafel
potentiostat
micro-hardness
10xDPBS; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2106563.pdf Link otwiera się w nowym oknie
Opis:: Biodegradable materials represent a new class of biocompatible materials with applications in many medical cases where the support must be provided only for a certain period. In this article obtaining of ZnMgY alloy is presented along with some basic characteristic investigations like chemical composition (energy dispersive spectroscopy - EDS), microstructure (optical microscopy - OM and scanning and electron microscopy - SEM), immersion behavior in 10xDPBS (Dulbecco Phosphate Buffer Saline) solution (mass loss and surface degradation), electro-corrosion behavior (potentiostat with a three electrodes cell) and micro-hardness of the experimental alloy compared to cast Zn and ZnMg materials. The results present an improvement of micro-hardness of Zn by alloying with Mg and Y and a modification of corrosion resistance.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Influence of Different Torsion Pitch on Microstructural Evolution and Strengthening Mechanism of Al Wires
Autorzy:: Sedighi, M.
Vaezi, A.
Pourbashiri, M.
Tematy:: torsion deformation
tensile test
micro hardness
microstructure
Al wire; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/351811.pdf Link otwiera się w nowym oknie
Opis:: This paper focused on the effect of pure torsion deformation and various torsion pitches on the mechanical properties of the commercial pure Al wires which has not been examined so far. The initial wires with diameter of 4 mm have been torsion deformed to different pitch length (PL). In order to investigate the effect of gradient microstructure caused by torsion deformation, three different pitch length of 15 mm, 20 mm and 30 mm are considered. The results revealed that the level of grain refinement is correlated with the amount of induced plastic shear strain by torsion deformation. For the wire with pitch length of 15 mm, the grain sizes decreased to about 106 μm and 47 μm in the wire center and edge from the initial size of about 150 μm of the annealed wire. The micro-hardness measurement results show a gradient distribution of hardness from the wire center to the wire surface that confirmed the increasing trend of plastic shear strain obtained by FE simulations. The hardness of annealed sample (35 HV) is increased up to 73 HV at the wire surface for the smallest pitch length. The yield and ultimate tensile strength of the torsion deformed wires are also increased up to about 85 MPa and 152 MPa from the initial values of 38 MPa and 103 MPa of the annealed one respectively while the maximum elongation reduced significantly.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Effect of Forge Application on Microstructural and Mechanical Properties of AISI 316 Using Direct Drive Friction Welding Process
Autorzy:: Hassan, Jabbar A.
Boukharouba, T.
Miroud, D.
Tematy:: friction welding
forge phase
micro-hardness
ultimate tensile strength
X-ray diffraction; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2125543.pdf Link otwiera się w nowym oknie
Opis:: Present study introduces effect of forge application and elimination on microstructural and mechanical properties of AISI 316 during friction welding. Temperature measurements, microstructure, micro-hardness, tensile test, scanning electron microscopy and X-ray diffraction were evaluated. Maximum temperature recorded was 819°C while forge was applied between 357°C-237°C. Thermo-mechanically affected zone and highly plastically deformed zone were created at the interface at elimination and application of forge respectively. Ultimate tensile strength decreased and ductility increased when forge elimination compared to forge application. Tensile fracture was occurred adjacent to the welding interface for both cases, though, after forge application, ductile fracture mode and cleavage features through the fingerprints were observed in the fracture morphology. Redistribution and concentration of gamma iron in 111 level after forge application and heat treated of AISI 316.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Microstructure and Mechanical Properties of Stainless Steel/Aluminum Multilayer Composites by One-Step Explosive Welding
Autorzy:: Hu, Xiaoyan
Liu, Yingbin
Yang, Li
Huang, Xiaochen
Tematy:: multilayer composites
one-step explosive welding
bonding interface
micro-hardness
mechanical properties; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/59110600.pdf Link otwiera się w nowym oknie
Opis:: The stainless steel/aluminum multilayer composites were prepared by one-step explosive welding using ammonium nitrate explosive with two different thicknesses. The microstructure and mechanical properties of the multilayer composites were examined. There is a thin metallurgical melting zone at each bonding interface, consisting mostly of iron and aluminum elements. However, the micro-crack appears in the second metallurgical bonding zone obtained using the explosive of 24 mm thickness. The microhardness values at the four bonding interfaces are higher than those of bulk 1060 aluminum and 304 stainless steel. The yield strength of the multilayer composites obtained in the two cases is higher than that of the original 304 stainless steel while the tensile strength is between those of the original 1060 aluminum and 304 stainless steel. Meanwhile, the tensile strength and yield strength of multilayer composites obtained by explosive welding with explosive of 20 mm thickness are relatively higher.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Friction and Wear Behavior of Direct Metal Deposition on SUH3
Autorzy:: Choi, Byungjoo
Cho, In-Sik
Jung, Do-Hyun
Lee, Moon G.
Jeon, Yongho
Tematy:: direct metal deposition
heat pretreatment
friction test
wear test
micro-hardness; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/352111.pdf Link otwiera się w nowym oknie
Opis:: Poppet valves made from high-frequency heat-treated SUH3 steel have insufficient durability, and scratches appear on the valve face in prolonged use. It is necessary to develop surface treatment technology with excellent durability to prevent the deterioration of engine performance. Therefore, a surface treatment technology with higher abrasion resistance than existing processes was developed by direct metal deposition to the face where the cylinder and valve are closed. In this study, heat pretreatment and deposition tests were performed on three materials to find suitable powders. In the performance evaluation, the hardness, friction coefficient, and wear rate were measured. Direct metal deposition using Inconel 738 and Stellite 6 powders without heat pretreatment were experimentally verified to have excellent durability.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Productivity and reliability improvement in turning Inconel 718 alloy : case study
Poprawa produktywności i niezawodności toczenia stopu Inconel 718 : studium przypadku
Autorzy:: Zębala, W.
Słodki, B.
Struzikiewicz, G.
Tematy:: Inconel
turning
productivity
optimization
parameters
micro-hardness
toczenie
produktywność
optymalizacja
parametry
mikrotwardość; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:: https://bibliotekanauki.pl/articles/1366203.pdf Link otwiera się w nowym oknie
Opis:: The paper presents an investigation of Inconel 718 alloy finishing turning, using a procedure that allows the optimal cutting data to be found with a maximization of the metal removal rate as the optimization criterion. The optimization procedure does not allow the required values of the chosen surface roughness indicator, cutting force and cutting tool wedge temperature to be exceeded at the same time. The optimization procedure includes the preliminary cutting tests for establishing the range of cutting data (feed and depth of cut) for the correct chip breaking as well as research concerning micro-hardness measurements which enables the cold work zone to be determined and the minimal value of the feed to be defined. The functionality of the algorithm was verified by using the improvement in machining productivity and reliability of an aircraft engine element as an example.
Artykuł opisuje badania obróbki wykończeniowej toczeniem stopu Inconel 718, mające na celu optymalizację parametrów skrawania z uwzględnieniem maksymalizacji objętościowej wydajności obróbki, jako kryterium optymalizacyjnego. Proponowana procedura uwzględnia wymagane w procesie ograniczenia dotyczące wartości parametru chropowatości obrabianej powierzchni, siły skrawania oraz maksymalnej temperatury w strefie skrawania. Procedura optymalizacyjna zawiera wstępne testy mające na celu ustalenie w lokalnych warunkach obróbki użytecznego zakresu parametrów skrawania (posuwu i głębokości skrawania) dla otrzymania korzystnej postaci wiórów. Wykonane pomiary mikrotwardości w strefie skrawania umożliwiły określenie wielkości strefy zgniotu warstwy wierzchniej, co z kolei pozwoliło na zdefiniowanie minimalnej wartości posuwu. Procedurę optymalizacyjną zweryfikowano na przykładzie obróbki wybranej powierzchni elementu silnika lotniczego. Osiągnięto znaczną poprawę produktywności i niezawodności procesu obróbki.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Microstructural Characteristics of Ti-Al-Dy Alloy Produced by High Energy Ball Milling
Autorzy:: Kim, Yuri
Rhee, Hoseong
Chang, Si Young
Tematy:: high energy ball milling
Ti-Al-Dy powders
SPS
microstructure
micro-hardness; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2049319.pdf Link otwiera się w nowym oknie
Opis:: In this study, the alloying of Ti, Al and Dy powders by high energy ball milling, and the spark plasma sintering (SPS) characteristics of as milled powders have been investigated based on the observation of microstructure. Pure Ti, 6wt% Al and 4wt% Dy powders were mixed and milled with zirconia balls at 600 ~ 1000 rpm for 3h in an Ar gas. The initial sizes of Ti, Al and Dy powders were approximately 20, 40, and 200 μm, respectively. With increasing the milling speed from 600 to 1000 rpm, the size of mixing powders reduced from 120 to 15 μm. On the other hand, from XRD results of powders milled at higher speeds than 700rpm, the peaks of Ti3Al and AlDy phases were identified, indicating the successful alloying. Therefore, the powders milled at 800 rpm have been employed for the SPS under the applied pressure of 50 MPa at 1373K for 15 min. In the SPSed sample, the Al3Dy and two ternary Ti-Al-Dy phases were newly detected, while the peak of AlDy phase disappeared. The SPSed Ti-6Al-4Dy alloy revealed high relative density and micro-hardness of approximately 99% and 950Hv, respectively.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Optimization of Process Parameters of Ultrasonic Welding on Dissimilar Metal Joints
Autorzy:: Mohan Kumar, Anand
Rajasekar, R.
Karthik, Vaduganathan
Kheawhom, Soorathep
Tematy:: 3105-H18 aluminium alloy
pure copper
ultrasonic welding
optimization
micro-hardness; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2049410.pdf Link otwiera się w nowym oknie
Opis:: Nowadays the automotive industry mostly prefers innovative solid-state welding technologies that would enable to welding of lightweight and high-performance materials. In this work, 3105-H18 Aluminium alloy (Al) and pure Copper (Cu) specimens with 0.5 mm thickness have been ultrasonically welded in a dissimilar (Al-Cu) manner. Optimization of process parameters of ultra-sonic welding has been carried out through full factorial method, three levels of variables considered for this experimental studies namely, weld pressure, amplitude, and time, also each variable interaction with welding strength has been studied. Additionally, micro-hardness and microstructure investigation in welded joints has been studied. The result shows that the weld strength greatly influenced weld amplitude at a medium and higher level of weld pressure. The interface micro-hardness of the welded joint has lower compared to the base metal.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Microstructure and Mechanical Properties of Stainless Steel/Aluminum Multilayer Composites by One-Step Explosive Welding
Autorzy:: Hu, Xiaoyan
Liu, Yingbing
Yang, Li
Huang, Xiaochen
Tematy:: multilayer composites
one-step explosive welding
bonding interface
micro-hardness
mechanical properties; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/59110728.pdf Link otwiera się w nowym oknie
Opis:: The stainless steel/aluminum multilayer composites were prepared by one-step explosive welding using ammonium nitrate explosive with two different thicknesses. The microstructure and mechanical properties of the multilayer composites were examined. There is a thin metallurgical melting zone at each bonding interface, consisting mostly of iron and aluminum elements. However, the micro-crack appears in the second metallurgical bonding zone obtained using the explosive of 24 mm thickness. The micro-hardness values at the four bonding interfaces are higher than those of bulk 1060 aluminum and 304 stainless steel. The yield strength of the multilayer composites obtained in the two cases is higher than that of the original 304 stainless steel while the tensile strength is between those of the original 1060 aluminum and 304 stainless steel. Meanwhile, the tensile strength and yield strength of multilayer composites obtained by explosive welding with explosive of 20 mm thickness are relatively higher.
Dostawca treści:: Biblioteka Nauki

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