CURRENT STATUS AND WAYS OF INCREASING WEAR RESISTANCE OF EDGE TOOLS OVER A WIDE RANGE OF CUTTING SPEEDS

Author(s):  
Denis Gennadyevich Shaturov ◽  
Gennady Filippovich Shaturov ◽  
Maksim Vladimirovich Pankov
Author(s):  
B. J. Hockey

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.


Alloy Digest ◽  
1993 ◽  
Vol 42 (2) ◽  

Abstract Durcomet 100 is an improved version of Alloy CD-4 MCu with better corrosion and wear resistance. The alloy is used in the annealed condition and possesses excellent corrosion resistance over a wide range of corrosion environments. Mechanical strength is also very high. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating and joining. Filing Code: SS-540. Producer or source: Duriron Company Inc.


Alloy Digest ◽  
2001 ◽  
Vol 50 (10) ◽  

Abstract CPM Rex 121 is a super high-speed steel with significantly higher wear resistance and red hardness than other high-speed steels. It is best suited for applications requiring high cutting speeds. It may provide an alternative to carbide where carbide cutting edges are too fragile. The annealed hardness is approximately 350-400 HB, and maximum hardness is approximately 72 HRC. This datasheet provides information on composition, physical properties, microstructure, hardness, and elasticity as well as fracture toughness. It also includes information on high temperature performance and wear resistance as well as heat treating and surface treatment. Filing Code: TS-591. Producer or source: Crucible.


2019 ◽  
Vol 20 (12) ◽  
pp. 1227-1243
Author(s):  
Hina Qamar ◽  
Sumbul Rehman ◽  
D.K. Chauhan

Cancer is the second leading cause of morbidity and mortality worldwide. Although chemotherapy and radiotherapy enhance the survival rate of cancerous patients but they have several acute toxic effects. Therefore, there is a need to search for new anticancer agents having better efficacy and lesser side effects. In this regard, herbal treatment is found to be a safe method for treating and preventing cancer. Here, an attempt has been made to screen some less explored medicinal plants like Ammania baccifera, Asclepias curassavica, Azadarichta indica, Butea monosperma, Croton tiglium, Hedera nepalensis, Jatropha curcas, Momordica charantia, Moringa oleifera, Psidium guajava, etc. having potent anticancer activity with minimum cytotoxic value (IC50 >3μM) and lesser or negligible toxicity. They are rich in active phytochemicals with a wide range of drug targets. In this study, these medicinal plants were evaluated for dose-dependent cytotoxicological studies via in vitro MTT assay and in vivo tumor models along with some more plants which are reported to have IC50 value in the range of 0.019-0.528 mg/ml. The findings indicate that these plants inhibit tumor growth by their antiproliferative, pro-apoptotic, anti-metastatic and anti-angiogenic molecular targets. They are widely used because of their easy availability, affordable price and having no or sometimes minimal side effects. This review provides a baseline for the discovery of anticancer drugs from medicinal plants having minimum cytotoxic value with minimal side effects and establishment of their analogues for the welfare of mankind.


2019 ◽  
Vol 20 (1_suppl) ◽  
pp. 38-44
Author(s):  
Mizuya Fukasawa

At the second Dialysis Access Symposium held in Nagoya, Japan, a proposal was made to investigate the differences in vascular access methods used in different countries. In this article, we describe the management of vascular access in Japan. The Japanese population is rapidly aging, and the proportion of elderly patients on dialysis is also increasing. There were 325,000 dialysis patients in Japan at the end of 2015, of whom 65.1% were aged 65 years or above. The number of patients with diabetic nephropathy or nephrosclerosis as the underlying condition is also increasing, whereas the number with chronic glomerulonephritis is steadily decreasing. The Japanese health insurance system enables patients to undergo medical treatment at almost no out-of-pocket cost. Percutaneous transluminal angioplasty suffers from a severe device lag compared with other countries, but although there are limitations on permitted devices, the use of those that have been authorized is covered by medical insurance. One important point that is unique to Japan is that vascular access is performed and managed by doctors involved in dialysis across a wide range of disciplines, including nephrologists, surgeons, and urologists. This may be one factor contributing to the good survival prognosis of Japanese dialysis patients.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 611
Author(s):  
Waldemar Gawron ◽  
Jan Sobieski ◽  
Tetiana Manyk ◽  
Małgorzata Kopytko ◽  
Paweł Madejczyk ◽  
...  

This paper presents the current status of medium-wave infrared (MWIR) detectors at the Military University of Technology’s Institute of Applied Physics and VIGO System S.A. The metal–organic chemical vapor deposition (MOCVD) technique is a very convenient tool for the deposition of HgCdTe epilayers, with a wide range of compositions, used for uncooled infrared detectors. Good compositional and thickness uniformity was achieved on epilayers grown on 2-in-diameter, low-cost (100) GaAs wafers. Most growth was performed on substrates, which were misoriented from (100) by between 2° and 4° in order to minimize growth defects. The large lattice mismatch between GaAs and HgCdTe required the usage of a CdTe buffer layer. The CdTe (111) B buffer layer growth was enforced by suitable nucleation procedure, based on (100) GaAs substrate annealing in a Te-rich atmosphere prior to the buffer deposition. Secondary-ion mass spectrometry (SIMS) showed that ethyl iodide (EI) and tris(dimethylamino)arsenic (TDMAAs) were stable donor and acceptor dopants, respectively. Fully doped (111) HgCdTe heterostructures were grown in order to investigate the devices’ performance in the 3–5 µm infrared band. The uniqueness of the presented technology manifests in a lack of the necessity of time-consuming and troublesome ex situ annealing.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Jarosław Mikuła ◽  
Daniel Pakuła ◽  
Ludwina Żukowska ◽  
Klaudiusz Gołombek ◽  
Antonín Kříž

The article includes research results for the functional properties achieved for a wide range of sintered tool materials, including sintered carbides, cermets and three types of Al2O3 oxide tool ceramics ((Al2O3 + ZrO2, Al2O3 + TiC and Al2O3 + SiC(w)) with (Ti,Al)N coating deposited in the cathodic arc evaporation (CAE-PVD) method and comparison with uncoated tool materials. For all coated samples, a uniform wear pattern on tool shank was observed during metallographic analysis. Based on the scanning electron microscope (SEM) metallographic analysis, it was found that the most common types of tribological defects identified in tested materials are: mechanical defects and abrasive wear of the tool side, crater formation on the tool face, cracks on the tool side, chipping on the cutting edge and built-up edge from chip fragments. Deposition of (Ti,Al)N coating on all tested substrates increases the wear resistance and also limits the exceeding of critical levels of permanent stresses. It even increases the tool life many times over. Such a significant increase in tool life results, among other things, from a large increase in microhardness of PVD coated materials compared to uncoated samples, increased resistance to thermal and chemical abrasion, improved chip formation and removal process conditions. Use of hard coatings applied to sintered tool materials is considered to be one of the most important achievements in improving the functional properties of cutting tools and can still be developed by improving the coating structure solutions (sorted and nanocrystalline structures) and extending the range of coating applications (Ti,Al)N in a variety of substrates.


2017 ◽  
Vol 474 (17) ◽  
pp. 2953-2976 ◽  
Author(s):  
Lasse Stach ◽  
Paul S. Freemont

The AAA+ (ATPases associated with diverse cellular activities) ATPase p97 is essential to a wide range of cellular functions, including endoplasmic reticulum-associated degradation, membrane fusion, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) activation and chromatin-associated processes, which are regulated by ubiquitination. p97 acts downstream from ubiquitin signaling events and utilizes the energy from ATP hydrolysis to extract its substrate proteins from cellular structures or multiprotein complexes. A multitude of p97 cofactors have evolved which are essential to p97 function. Ubiquitin-interacting domains and p97-binding domains combine to form bi-functional cofactors, whose complexes with p97 enable the enzyme to interact with a wide range of ubiquitinated substrates. A set of mutations in p97 have been shown to cause the multisystem proteinopathy inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia. In addition, p97 inhibition has been identified as a promising approach to provoke proteotoxic stress in tumors. In this review, we will describe the cellular processes governed by p97, how the cofactors interact with both p97 and its ubiquitinated substrates, p97 enzymology and the current status in developing p97 inhibitors for cancer therapy.


Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5826
Author(s):  
Yinming Zhao ◽  
Yang Liu ◽  
Yongqian Li ◽  
Qun Hao

Resistance strain force sensors have been applied to monitor the strains in various parts and structures for industrial use. Here, we review the working principles, structural forms, and fabrication processes for resistance strain gauges. In particular, we focus on recent developments in resistance stress transfer for resistance strain force sensors and the creep effect due to sustained loads and/or temperature variations. Various error compensation methods to reduce the creep effect are analyzed to develop a metrology standard for resistance strain force sensors. Additionally, the current status of carbon nanotubes (CNTs), silicon carbide (SiC), gallium nitride (GaN), and other wide band gap semiconductors for a wide range of strain sensors are reviewed. The technical requirements and key issues of resistance strain force sensors for future applications are presented.


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