Effect of Laser Pre-Treatment on the Machining Performance of Aluminum/SiC MMC

2003 ◽  
Vol 125 (4) ◽  
pp. 378-384 ◽  
Author(s):  
Stuart Barnes ◽  
Richard Morgan ◽  
Andrew Skeen

Although the abrasive reinforcement in MMCs primarily controls their machining behavior, the properties of the matrix also exert an influence. A 1200 W diode laser was used, due to the large footprint (5×0.3 mm) and the short wavelength (0.94 μm) to pre-treat a 2618 (18% SiC) alloy. The laser heating and self-quenching of the material modified the matrix properties. Machining performance was then assessed by measuring tool wear and edge condition, cutting forces, surface finish, and sub-surface damage. Results indicated that pre-treatment gave less wear, lower forces, and less sub-surface damage although abrasion remained the primary wear mechanism.

2012 ◽  
Vol 497 ◽  
pp. 299-303 ◽  
Author(s):  
Guo Fu Gao ◽  
Yan Yan Zhao ◽  
Xing Hui Ma

The experimental research on ultrasonic vibration assisted milling non-ablating carbon fibre reinforced carbon composite was carried out by employing uncoated tungsten carbide milling cutter, in order to reduce the machining cost and improve the surface quality of workpiece. According to the experimental results, the tool wear was reduced and the surface quality of milled carbon fibre reinforced carbon composite was improved. Compared to traditional milling method, the flank wear land was narrowed and it dominated by abrasive particles wear mechanism. The wear trace was even and wide, with width of 7-8μm; while the rake face was worn in the mode of adhesion wear mechanism. Most of carbon fibres were cut off directly and there were little fracture, pull-out and delamination; the matrix phase was removed nearly in hybrid of brittle and ductile regime and surface damage was small.


2010 ◽  
Vol 443 ◽  
pp. 324-329 ◽  
Author(s):  
Bin Zou ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Jin Peng Song

Si3N4/TiN nanocomposite tool and Si3N4/Ti(C7N3) nanocomposite tool were prepared. The cutting performance and wear mechanism of Si3N4-based nanocomposite ceramic tool was investigated by comparison with a commercial sialon ceramic tool in machining of 45 steel. Si3N4-based nanocomposite ceramic tool exhibits the better wear resistance than sialon at the relatively high cutting speed. The increased cutting performance of Si3N4-based nanocomposite ceramic tool is ascribed to the higher mechanical properties. Nano-particles can refine the matrix grains and improve the bonding strength among the matrix grains of Si3N4-based nanocomposite ceramic tool materials. It contributes to an improved wear resistance of the cutting tools during machining.


2018 ◽  
Vol 108 (10) ◽  
pp. 736-742
Author(s):  
J. Hartig ◽  
B. Kirsch ◽  
J. Aurich

Mit Schneidkantenpräparation kann das Werkzeug im Zerspanprozess an die Bearbeitungsaufgabe angepasst werden. Homogene Präparationen können dabei entweder auf hohe Belastungen des Werkzeugs oder ein optimiertes Bearbeitungsergebnis im Sinne der Oberfläche ausgelegt werden. In diesem Beitrag wurden die Schneidkanten von Hartmetall-Wendeschneidplatten unterschiedlich inhomogen präpariert, um den unterschiedlichen Anforderungen entlang des Eingriffs Rechnung zu tragen. Neben der Werkzeugstandzeit wurde das Prozessergebnis beim Außenlängs-Runddrehen von ausferritischem Gusseisen (ADI) 900 untersucht.   The preparation of cutting edges allows for tools to be tailored to the machining process. A homogeneous preparation can either be designed for high loads in the machining process or an optimized machining result on the surface. In this article, the cutting edges of tungsten carbide indexable inserts were prepared inhomogeneously and thus individually matched to the machining task. Tool life and machining performance while turning austempered ductile iron (ADI) 900 were investigated.


Author(s):  
Sandro Turchetta ◽  
Luca Sorrentino ◽  
Gianluca Parodo

Diamond tools suitable for machining operations of natural stones can be divided into two groups: cutting tools, including blades, the circular blades and the wires, and the surface machining ones, involving mills and grinders, that can be of different shapes. For the stone sawing process, the most adopted tool type is the diamond mill, whose duration and performance are influenced by various elements such as: the mineralogical characteristics of the material to be machined; the working conditions such as the depth of cut, the feed rate and the spindle speed; the production process of the diamond segment and the characteristics of both the matrix and the diamond, such as the size, the type and the concentration of the diamonds and the metal bond formulation hardness. This work allows to indirectly assess the wear of sintered diamond tools by signal analysis (in time and frequency domain) of the cutting force components acquired in the process. The results obtained represent a fundamental step for the development of a sensory supervision system capable of assessing the tool wear and hence to modify the process parameters in process, in order to optimize cutting performance and tool life.


Author(s):  
Kshitij Pandey ◽  
Saurav Datta

The present work investigates application feasibility of PVD TiN/TiCN/TiN coated cermet and CVD Al2O3/TiCN coated SiAlON for dry machining of Inconel 825 superalloy. Machining performance is interpreted through cutting force magnitude, tool-tip temperature, and mechanisms of tool wear. Results are compared to that of CVD multi-layer TiN/TiCN/Al2O3/TiN coated WC-Co tool. It is evidenced that SiAlON tool generates lower cutting force but experiences higher tool-tip temperature than other two counterparts. Apart from abrasion and adhesion, carbide tool witnesses coating peeling and ploughing. In contrast, SiAlON tool suffers from inexorable chipping and notching. Wear pattern of cermet tool seems less severe than carbide and SiAlON. Chip's underside surface morphology appears relatively better in case of cermet tool.


2016 ◽  
Vol 31 (3) ◽  
pp. 642-657 ◽  
Author(s):  
J. Hassler ◽  
R. Matschat ◽  
S. Richter ◽  
P. Barth ◽  
A. K. Detcheva ◽  
...  

Experiments with SF6, NF3, CF4and H2as new modifier gases for the matrix studied were performed. Pre-treatment steps of sub-samples (e.g., roasting) can now be omitted; the scope of application was enlarged to Au and hydride forming elements (such as Se, Te).


Author(s):  
Yusuf Kaynak ◽  
Armin Gharibi

Titanium alloy Ti-5Al-5V-3Cr-0.5Fe (Ti-5553) is a new generation of near-beta titanium alloy that is commonly used in the aerospace industry. Machining is one of the manufacturing methods to produce parts that are made of this near-beta alloy. This study presents the machining performance of new generation near-beta alloys, namely, Ti-5553, by focusing on a high-speed cutting process under cryogenic cooling conditions and dry machining. The machining experiments were conducted under a wide range of cutting speeds, including high speeds that used liquid nitrogen (LN2) and carbon dioxide (CO2) as cryogenic coolants. The experimental data on the cutting temperature, tool wear, force components, chip breakability, dimensional accuracy, and surface integrity characteristics are presented and were analyzed to evaluate the machining process of this alloy and resulting surface characteristics. This study shows that cryogenic machining improved the machining performance of the Ti-5553 alloy by substantially reducing the tool wear, cutting temperature, and dimensional deviation of the machined parts. The cryogenic machining also produced shorter chips as compared to dry machining.


2021 ◽  
Vol 2103 (1) ◽  
pp. 012100
Author(s):  
V A Bershtein ◽  
A M Fainleib ◽  
D A Kirilenko ◽  
P N Yakushev

Abstract The study of nanostructure, thermal and relaxation properties (by HAADF-STEM, EDXS, DMA and DSC), combined with the calculations of interparticle distances and interfacial areas, has been performed for a series of the hybrid Cyanate Ester Resin (CER)/Si02 polymer composites with 0.01 to 10 wt.% Si02 units introduced via a sol-gel process. The absence of clusterization, arising only subnanometric Si02 nodes and their quasi-regular distribution within the amorphous matrix, with the shortest distances between nodes, provided their exceptional positive impact on the matrix properties at ultra-low Si02 contents of 0.03-0.1 wt.%. The superiority of these subnanocomposites over the nanocomposites was determined by the role of constrained interfacial dynamics over the whole matrix.


2007 ◽  
Vol 55 (12) ◽  
pp. 119-125 ◽  
Author(s):  
L. Mansouri ◽  
L. Bousselmi ◽  
A. Ghrabi

Biological pre-treated landfill leachates of Djebel Chakir contains some macromolecular organic substances that are resistant to biological degradation. The aim of the present work is to assess the feasibility of removing refractory organic pollutants in biological pre-treated landfill leachate by solar photocatalyse process. Leachate pollutant contents are studied to assess their contribution to leachate pollution and their treatability by solar photocatalyse process. Phenol is chosen as model of pollutants, to evaluate its removal and the efficiency of the photocatalytic system. The experiments were carried out in suspended photocatalytic reactor, using TiO2 Degussa P25, under sunlight illumination (UV-A: 15–31 W/cm2). Under optimum operational conditions, applied to single reactant (phenol), the system presents a TOC removal of 90% (the degradation follows a first-order kinetic). Based on the TOC removal, the results shows that the degradation of biological pre-treated leachate follows a zero-order kinetic. After 5 h of sunlight exposure, 74% of COT is removed. The TOC removal is the best without any correction of the pH and at the TiO2 concentration of 2.5 g/L. The photocatalytic degradation of organic contaminants as well as the formation and disappearance of the by-products were followed by GC/MS. The solar photocatalysis processes induce several modifications of the matrix leading to more biodegradable forms: all the remaining and new compounds generated after the biological pre-treatment of leachate are degraded and other types of organics appear, mainly carboxylic acid, aliphatic hydrocarbons and phtalic acids.


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