Experimental Correlation between Metallurgical Parameters, Hardness and Machinability of 319 Al-Si-Cu-Mg Alloys

An attempt has been made to quantify the effects of alloying elements and aging parameters on the hardness and machinability of heat-treated 319 alloys containing α-Fe or β-Fe intermetallics An understanding of these parameters would help in selecting the metallurgical conditions required to achieve the optimum and maximum productivity at high speed machining. Hardness measurements were carried out on specimens prepared from 319 alloys in the as-cast and heat-treated conditions, using different combinations of grain refining, Sr-modification, and alloying additions. Aging treatments were carried out at 155°C, 180°C, 200°C, and 220°C for 4 h, followed by air cooling, as well as at 180°C and 220°C for 2, 4, 6, and 8 h to determine conditions under which specific hardness levels could be obtained. Statistical design of experiments is a satisfactory method for quantifying the effect of various parameters. Experimental correlations of the results obtained from the hardness measurements are analyzed and correlations that relate the alloying additions and heat treatment to the hardness of such alloys are found. Two levels of magnesium content (%Mg), volume fractions of the Fe-intermetallics (%V.F), Sr-modification (Sr-ppm), aging parameters (temperature and time) were tested: 0.1% and 0.28% for Mg, 2% and 5% for Fe-intermetallics (%V.F), 0-ppm and 200-ppm for Sr-modification, 180°C and 220°C for aging temperature and 2h. and 8h. for aging time. Experimental correlations between the metallurgical parameters and the machinability values obtained were analyzed. For this, two levels of Mg (0.1 and 0.28 wt%), Fe-intermetallics (2% and 5%), and two aging temperatures (180°C and 220°C) and aging time of 2h were selected.

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Experimental Correlation for the Effect of Metallurgical Parameters on the Hardness of 356 and 319 Aluminum Alloys Using Minitab Software

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.716.15 ◽

2013 ◽

Vol 716 ◽

pp. 15-24

Author(s):

Mahmoud M. Tash ◽

S. Alkahtani

Keyword(s):

Peak Hardness ◽

Air Cooling ◽

Alloying Additions ◽

Sr Modification ◽

Aging Period ◽

Heat Treated ◽

Experimental Correlation ◽

Hardness Peak ◽

Fe Intermetallics ◽

Hardness Values

The present study was undertaken to investigate the effect of metallurgical parameters on the hardness and microstructural characterisations of as-cast and heat-treated 356 and 319 alloys, with the aim of adjusting these parameters to produce castings of suitable hardness and Fe-intermetallic volume fractions for subsequent use in studies relating to the machinability of these alloys. Hardness measurements were carried out on specimens prepared from 356 and 319 alloys in the as-cast and heat-treated conditions, using different combinations of grain refining, Sr-modification, and alloying additions. Aging treatments were carried out at 155 °C, 180 °C, 200 °C, and 220 °C for 4 h, followed by air cooling, as well as at 180 °C and 220 °C for 2, 4, 6, and 8 h. Peak hardness was observed in 356 alloys when aging was carried out at 180oC/4h. In the case of unmodified or modified 356 alloys containing mostly α-Fe intermetallics, aging at 180 °C up to 8h produced a sharp rise in hardness during the first two hours of aging, followed by a broad peak or plateau over the 2-8 h aging period. Aging at 220 °C revealed a hardness peak at 2h aging time for both 356 and 319 alloys. Addition of Mg to unmodified or modified 319 alloys produced a remarkable increase in hardness at all aging temperatures. This may be explained on the basis of the combined effect of Cu-and Mg-intermetallics in the 319 alloys, where hardening during aging occurs by the cooperative precipitation of Al2Cu and Mg2Si phase particles.[, ] For 356 and 384 alloys, the Mg-containing 319 alloys (~same Mg concentration as in 356 alloys) displayed higher hardness values than the 356 alloys for the aged condition, where hardening occurs by cooperative precipitation of Al2Cu and Mg2Si phase particles in 319 alloys compared to only Mg2Si precipitation in the case of 356 alloys.

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Effect of Mg, Sr, Ti and Aging Parameters on the Mechanical Behavior of 319 Alloys in the T5 and T6 Heat Treatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.482-484.2275 ◽

2012 ◽

Vol 482-484 ◽

pp. 2275-2288

Author(s):

Saleh Alkahtani

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Aging Treatment ◽

Magnesium Content ◽

Air Cooling ◽

Particle Spacing ◽

Sr Modification ◽

Heat Treated ◽

Negative Effect ◽

Mg Content

In this work, the effect of metallurgical parameters (i.e. alloy chemistry and aging parameters) on the mechanical properties of 319 alloys was investigated, with the aim of adjusting these parameters to produce castings of suitable mechanical properties. An attempt has been made to quantify the effects of alloying elements (Mg, Sr, and Ti) and aging parameters on the mechanical properties of heat-treated (T5 and T6) 319 alloys. Exploring the heat treatment differences between T5 and T6 for 319 alloys would help in selecting the metallurgical conditions required to achieve the optimum and maximum mechanical properties. Aging treatments were carried out for 319 alloys in the T5- and T6-condition at 150°C, 180°C, 200°C, 220°C and 250°C for 4, 8, 16, 24 and 48 h, followed by air cooling. Aging treatment at a lower temperature of 150°C produces fine and dense precipitates having a smaller inter-particle spacing, while at higher aging temperatures, such as 250°C, the precipitates are coarser in size, less dense, and more widely dispersed. For 319 alloys, crack initiate and propagate mainly through the debonding of Si particles from the Al matrix and through the cleavage of β-iron intermetallics. Fracture of intermetallic phases in the interdendritic regions is mostly brittle, with the formation of microcracks at the Si, Cu, Fe-base intermetallics and aluminium interfaces. Experimental correlations of the results obtained from the mechanical properties measurements are analyzed and correlations that relate the alloying additions and heat treatment to the ultimate tensile strength (UTS), yield strength (YS) and total percent elongation (%E) of such alloys are found. Different levels of magnesium content (%Mg), Sr-modification (Sr-ppm), aging parameters (temperature and time) were tested. The effect of alloy additions (Mg, Sr and Ti) and aging heat treatment parameters (Temperature and Time) on the mechanical properties and alloy performance of cast and heat treated 319 alloys are investigated. It was found that the strength of 319 alloys increases with the magnesium content and decreases with the Sr-modification (Sr-ppm) and aging parameters (temperature and time). Increasing the Mg content in primary 319 alloys up to 0.45% enhances the alloy response to heat treatment in the T5 and T6 Tempers, more particularly, the T6 one. Sr-Modification of high Mg content 319 alloy in amounts of ~360 ppm leads to a noticeable decline in alloy strength due to porosity formation which counteracts the beneficial effect of the modification. Sr-modification has a negative effect on the % elongation results of Mg-content 319 alloys due to the Mg-Sr interaction in the aged-T6 conditions. However, grain refining of the Mg and Sr content 319 alloys produce sounder castings with finer grain sizes

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Crystallographic Differences of Metastable NI2MO in a NI-MO-AL Superalloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000672 ◽

1980 ◽

Vol 38 ◽

pp. 158-159

Author(s):

Michael M. Kersker ◽

E. A. Aigeltinger ◽

J. J. IIren

Keyword(s):

Mechanical Properties ◽

Air Cooling ◽

Solution Treated ◽

Heat Treated ◽

Metastable Compounds ◽

Rapidly Solidified

Ni-rich alloys based on approximate ternary composition Ni-8Mo-15A1 (at%) are presently under investigation in an attempt to study the contribution, if any, of the profusion of Mo-rich NixMo metastable compounds that these alloys contain to their excellent mechanical properties. One of the alloys containing metastable NixMo precipitates is RSR 197 of composition Ni-8.96Mo-15.06A1-1.98Ta-.015Yt. The alloy was prepared at Pratt and Whitney Government Products Division, West Palm Beach, Florida, from rapidly solidified powder. The powder was canned under inert conditions and extruded as rod at 1315°C. The as-extruded rod, after air cooling, was solution treated at 1315°C for two hours, air cooled, and heat treated for one hour at 815°C, followed again by air cooling.

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OPTIMIZATION OF CADMIUM DISSOLUTION FROM A HAZARDOUS WASTE BY STATISTICAL DESIGN OF EXPERIMENTS

Environmental Engineering and Management Journal ◽

10.30638/eemj.2014.334 ◽

2014 ◽

Vol 13 (12) ◽

pp. 2963-2970 ◽

Cited By ~ 6

Author(s):

Mahdi Gharabaghi ◽

Mehdi Irannajad ◽

Amir Reza Azadmehr

Keyword(s):

Design Of Experiments ◽

Hazardous Waste ◽

Statistical Design ◽

Statistical Design Of Experiments

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STATISTICAL DESIGN OF EXPERIMENTS FOR THE Cr(VI) ADSORPTION ON WEED Salvinia cucullata

Environmental Engineering and Management Journal ◽

10.30638/eemj.2013.058 ◽

2013 ◽

Vol 12 (3) ◽

pp. 465-474 ◽

Cited By ~ 3

Author(s):

Saroj Sundar Baral ◽

Ganesan Surendran ◽

Namrata Das ◽

Polisetty Venkateswara Rao

Keyword(s):

Design Of Experiments ◽

Statistical Design ◽

Statistical Design Of Experiments

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EXOCUT

Alloy Digest ◽

10.31399/asm.ad.ts0265 ◽

1973 ◽

Vol 22 (11) ◽

Keyword(s):

Fracture Toughness ◽

Surface Treatment ◽

Tool Steel ◽

High Speed ◽

Heat Treating ◽

Heat Treated

Abstract EXOCUT is a super high-speed tool steel capable of being heat treated to Rockwell C 70. It is well suited for machining hard and difficult-to-machine materials. This datasheet provides information on composition, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-265. Producer or source: Allegheny Ludlum Corporation.

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TATMO V

Alloy Digest ◽

10.31399/asm.ad.ts0434 ◽

1985 ◽

Vol 34 (1) ◽

Keyword(s):

Fracture Toughness ◽

Wear Resistance ◽

High Speed ◽

Heat Treating ◽

Steel Company ◽

Treated Steel ◽

Heat Treated ◽

Red Hardness ◽

Edge Toughness ◽

Heat Treated Steel

Abstract TATMO-V is a high-speed tool steel with superior abrasion resistance because of its high contents of carbon and vanadium. It is an excellent choice for premium grade tools which require an outstanding balance of red hardness, edge toughness, and wear resistance. Increased tool life of Tatmo-V is noted in the machining of semi-hard, heat-treated steel pats (300-350 Brinell). This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-434. Producer or source: Latrobe Steel Company.

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Synthesis of an Addition-Crosslinkable, Silicon-Modified Polyolefin via Reactive Extrusion Monitored by In-Line Raman Spectroscopy

Polymers ◽

10.3390/polym13081246 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1246

Author(s):

Steffen Ulitzsch ◽

Tim Bäuerle ◽

Mona Stefanakis ◽

Marc Brecht ◽

Thomas Chassé ◽

...

Keyword(s):

Raman Spectroscopy ◽

High Performance ◽

Process Analytical Technology ◽

Statistical Design ◽

Reactive Extrusion ◽

Statistical Design Of Experiments ◽

Grafting Efficiency ◽

Grafting Reaction ◽

Central Composite Experimental Design ◽

Process Factors

We present the modification of ethylene-propylene rubber (EPM) with vinyltetra-methydisiloxane (VTMDS) via reactive extrusion to create a new silicone-based material with the potential for high-performance applications in the automotive, industrial and biomedical sectors. The radical-initiated modification is achieved with a peroxide catalyst starting the grafting reaction. The preparation process of the VTMDS-grafted EPM was systematically investigated using process analytical technology (in-line Raman spectroscopy) and the statistical design of experiments (DoE). By applying an orthogonal factorial array based on a face-centered central composite experimental design, the identification, quantification and mathematical modeling of the effects of the process factors on the grafting result were undertaken. Based on response surface models, process windows were defined that yield high grafting degrees and good grafting efficiency in terms of grafting agent utilization. To control the grafting process in terms of grafting degree and grafting efficiency, the chemical changes taking place during the modification procedure in the extruder were observed in real-time using a spectroscopic in-line Raman probe which was directly inserted into the extruder. Successful grafting of the EPM was validated in the final product by 1H-NMR and FTIR spectroscopy.

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Evaluation of Cutting-Tool Coating on the Surface Roughness and Hole Dimensional Tolerances during Drilling of Al6061-T651 Alloy

Materials ◽

10.3390/ma14071783 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1783

Author(s):

Hamza A. Al-Tameemi ◽

Thamir Al-Dulaimi ◽

Michael Oluwatobiloba Awe ◽

Shubham Sharma ◽

Danil Yurievich Pimenov ◽

...

Keyword(s):

Surface Roughness ◽

Cutting Tool ◽

Good Practice ◽

Cutting Tools ◽

Statistical Design ◽

Cutting Parameters ◽

Statistical Design Of Experiments ◽

Hole Quality ◽

Coated Tools ◽

Tool Coating

Aluminum alloys are soft and have low melting temperatures; therefore, machining them often results in cut material fusing to the cutting tool due to heat and friction, and thus lowering the hole quality. A good practice is to use coated cutting tools to overcome such issues and maintain good hole quality. Therefore, the current study investigates the effect of cutting parameters (spindle speed and feed rate) and three types of cutting-tool coating (TiN/TiAlN, TiAlN, and TiN) on the surface finish, form, and dimensional tolerances of holes drilled in Al6061-T651 alloy. The study employed statistical design of experiments and ANOVA (analysis of variance) to evaluate the contribution of each of the input parameters on the measured hole-quality outputs (surface-roughness metrics Ra and Rz, hole size, circularity, perpendicularity, and cylindricity). The highest surface roughness occurred when using TiN-coated tools. All holes in this study were oversized regardless of the tool coating or cutting parameters used. TiN tools, which have a lower coating hardness, gave lower hole circularity at the entry and higher cylindricity, while TiN/TiAlN and TiAlN seemed to be more effective in reducing hole particularity when drilling at higher spindle speeds. Finally, optical microscopes revealed that a built-up edge and adhesions were most likely to form on TiN-coated tools due to TiN’s chemical affinity and low oxidation temperature compared to the TiN/TiAlN and TiAlN coatings.

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