scholarly journals Development of Precipitation Hardening Parameters for High Strength Alloy AA 7068

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 918
Author(s):  
Julia Osten ◽  
Benjamin Milkereit ◽  
Michael Reich ◽  
Bin Yang ◽  
Armin Springer ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Maximum Yield ◽  
High Strength ◽  
Tensile Tests ◽  
Age Hardening ◽  
Scanning Calorimetry ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
Kinetics Of

The mechanical properties after age hardening heat treatment and the kinetics of related phase transformations of high strength AlZnMgCu alloy AA 7068 were investigated. The experimental work includes differential scanning calorimetry (DSC), differential fast scanning calorimetry (DFSC), sophisticated differential dilatometry (DIL), scanning electron microscopy (SEM), as well as hardness and tensile tests. For the kinetic analysis of quench induced precipitation by dilatometry new metrological methods and evaluation procedures were established. Using DSC, dissolution behaviour during heating to solution annealing temperature was investigated. These experiments allowed for identification of the appropriate temperature and duration for the solution heat treatment. Continuous cooling experiments in DSC, DFSC, and DIL determined the kinetics of quench induced precipitation. DSC and DIL revealed several overlapping precipitation reactions. The critical cooling rate for a complete supersaturation of the solid solution has been identified to be 600 to 800 K/s. At slightly subcritical cooling rates quench induced precipitation results in a direct hardening effect resulting in a technological critical cooling rate of about 100 K/s, i.e., the hardness after ageing reaches a saturation level for cooling rates faster than 100 K/s. Maximum yield strength of above 600 MPa and tensile strength of up to 650 MPa were attained.

Detection of Quench Induced Precipitation in Al Alloys by Dilatometry

2016 ◽  
Vol 877 ◽  
pp. 147-152 ◽  
Author(s):  
Benjamin Milkereit ◽  
Michael Reich ◽  
Olaf Kessler
Keyword(s):  
Cooling Rate ◽  
High Strength ◽  
Al Alloys ◽  
Age Hardening ◽  
Controlled Cooling ◽  
Scanning Calorimetry ◽  
Cooling Rates ◽  
Precipitation Behaviour ◽  
In Situ Detection

Quenching is a critical step during the strengthening age hardening of Aluminium alloys. To obtain optimal technological results, parts should be quenched with the upper critical cooling rate. The precipitation behaviour of Al alloys during cooling from solution annealing and thereby the critical cooling rates are typically investigated by in-situ measurements with differential scanning calorimetry (DSC). Conventional DSCs are limited at cooling rates below 10 Ks-1. Unfortunately, medium to high strength Al alloys typically have critical cooling rates between 10 and some 100 Ks-1. Recently it was shown that dilatometry is generally able for in-situ detection of precipitation in Al alloys. Dilatometry allows controlled cooling up to some 100 Ks-1 and therefore covers the cooling rate range relevant. In this work, we aim to show up and discuss possibilities and limitations of dilatometric detection of quench induced precipitates in 2xxx, and 7xxx Al alloys. The basic method will be presented and results will be compared with DSC work.

scholarly journals Characterization of the Role of Squeeze Casting on the Microstructure and Mechanical Properties of the T6 Heat Treated 2017A Aluminum Alloy

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
S. Souissi ◽  
N. Souissi ◽  
H. Barhoumi ◽  
M. ben Amar ◽  
C. Bradai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Squeeze Casting ◽  
Applied Pressure ◽  
High Strength ◽  
Casting Process ◽  
Tensile Tests ◽  
Scanning Calorimetry ◽  
Microstructure And Mechanical Properties

In this study, the effects of squeeze casting process and T6 heat treatment on the microstructure and mechanical properties of 2017A aluminum alloy were investigated with scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), and microhardness and tensile tests. The results showed that this alloy contained α matrix, θ-Al2Cu, and other phases. Furthermore, the applied pressure and heat treatment refines the microstructure and improve the ultimate tensile strength (UTS) to 296 MPa and the microhardness to 106 HV with the pressure 90 MPa after ageing at 180°C for 6 h. With ageing temperature increasing to 320°C for 6 h, the strength of the alloy declines slightly to 27 MPa. Then, the yield strength drops quickly when temperature reaches over 320°C. The high strength of the alloy in peak-aged condition is caused by a considerable amount of θ′ precipitates. The growth of θ′ precipitates and the generation of θ phase lead to a rapid drop of the strength when temperature is over 180°C.

scholarly journals Effect of Strain on Transformation Diagrams of 100Cr6 Steel

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 326 ◽  
Author(s):  
Rostislav Kawulok ◽  
Ivo Schindler ◽  
Jaroslav Sojka ◽  
Petr Kawulok ◽  
Petr Opěla ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Uniaxial Compression ◽  
Martensite Formation ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
Transformation Diagrams ◽  
Kinetics Of

Based on dilatometric tests, the effect of various values of previous deformation on the kinetics of austenite transformations during the cooling of 100Cr6 steel has been studied. Dilatometric tests have been performed with the use of the optical dilatometric module of the plastometer Gleeble 3800. The obtained results were compared to metallographic analyses and hardness measurements HV30. Uniaxial compression deformations were chosen as follows: 0, 0.35, and 1; note that these are true (logarithmic) deformations. The highly important finding was the absence of bainite. In addition, it has been verified that with the increasing amount of deformation, there is a further shift in the pearlitic region to higher cooling rates. The previous deformation also affected the temperature martensite start, which decreased due to deformation. The deformation value of 1 also shifted the critical cooling rate required for martensite formation from the 12 °C/s to 25 °C/s.

CMW 100

Alloy Digest ◽  
2000 ◽  
Vol 49 (10) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Copper Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Age Hardening ◽  
High Tensile Strength ◽  
Electrical Components ◽  
Flash Welding ◽  
Hardening Heat Treatment

Abstract CMW 100 is a copper alloy that combines high tensile strength with high electrical and thermal conductivity. It responds to age-hardening heat treatment. It is used for flash welding dies, springs, electrical components, high-strength backing material for brazed assemblies, and wire guides. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: CU-29. Producer or source: CMW Inc. Originally published as Mallory 100, August 1955, revised October 2000.

CONFLEX 720

Alloy Digest ◽  
1964 ◽  
Vol 13 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Nickel Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Age Hardening ◽  
Copper Manganese ◽  
Hardening Heat Treatment

Abstract CONFLEX 720 is a copper-manganese-nickel alloy that responds to an age-hardening heat treatment for high strength and corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as heat treating, machining, joining, and surface treatment. Filing Code: Cu-143. Producer or source: Metals & Controls Inc..

ALUMINUM A356

Alloy Digest ◽  
1969 ◽  
Vol 18 (11) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Strength ◽  
Heat Treating ◽  
Age Hardening ◽  
Casting Alloy ◽  
Permanent Mold ◽  
Aluminum Company ◽  
Mold Casting ◽  
Hardening Heat Treatment

Abstract Aluminum A356 is a sand and permanent mold casting alloy that responds to an age-hardening heat treatment. It is recommended for aircraft and missile components where high strength and corrosion resistance are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on heat treating, machining, and joining. Filing Code: Al-192. Producer or source: Aluminum Company of America.

The effect of cooling rate on crystallization behavior and tensile properties of CF/PEEK composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang
Keyword(s):  
Cooling Rate ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Cooling Rates ◽  
Control Range ◽  
Temperature Range ◽  
Transverse Tensile

Abstract In this study, the differential scanning calorimetry (DSC) tests were performed to measure the nonisothermal crystallization behavior of carbon fiber reinforced polyether ether ketone (CF/PEEK) composites under different cooling rates. The characteristic parameters of crystallization were obtained, and the nonisothermal crystallization model was established. The crystallization temperature range of the material at different cooling rates was predicted by the model. The unidirectional laminates were fabricated at different cooling rates in the crystallization temperature range. The results showed that the crystallization temperature range shifted to a lower temperature with the increase of cooling rate, the established nonisothermal crystallization model was consistent with the DSC test results. It is feasible to shorten the cooling control range from the whole process to the crystallization range. The crystallinity and transverse tensile strength declined significantly with the increase of the cooling rate in the crystallization temperature range. The research results provided theoretical support for the selection of cooling conditions and temperature control range, which could be applied to the thermoforming process of semi-crystalline polymer matrixed composites to improve the manufacturing efficiency.

Effects of RE on Critical Cooling Rate of Bearing-B Steel

2012 ◽  
Vol 535-537 ◽  
pp. 761-763 ◽  
Author(s):  
Yi Sheng Zhao ◽  
Xin Ming Zhang ◽  
Zhi Guo Gao
Keyword(s):  
Phase Change ◽  
Cooling Rate ◽  
Experimental Results ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
The Law

The law of phase change of bearing-B steel during continual cooling was studied by adopting dilatometer. The CCT curves of bearing-B steel were drawn, and the effects of RE on critical cooling rates were studied. The experimental results show that the start temperatures of martensite TM was decreased from 438 to 404°C. The critical cooling rate was simultaneously decreased from 33 to 15°C/s.

scholarly journals Process chain for the fabrication of hardenable aluminium-zirconium micro-components by deep drawing

2018 ◽  
Vol 190 ◽  
pp. 15013 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Julien Kovac ◽  
Bernd Koehler ◽  
Axel von Hehl ◽  
Andreas Mehner ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnetron Sputtering ◽  
Deep Drawing ◽  
High Strength ◽  
Tensile Tests ◽  
Process Chain ◽  
Production Chain ◽  
Cold Forming ◽  
Industrial Sectors ◽  
Material State

Today, micro components are used in various industrial sectors such as electronics engineering and medical applications. The final quality of such parts depends on each individual step of the production chain from the manufacturing of semi-finished parts to the post-processing. In this study, magnetron sputtering is used to manufacture thin (15-30 μm) aluminium-zirconium alloy foils for the deep drawing of high strength and hardenable micro cups, which can be, for example, employed as micro valve caps. The development of a novel process chain for the production of these parts includes four different steps, beginning with the production of Al-Zr foils by magnetron sputtering. Secondly, tensile tests are performed with the foils in order to estimate their mechanical properties. Subsequently, micro deep drawing is used to produce the cup’s shape, and finally, a heat treatment in a drop-down tube furnace adjusts the cup’s hardness during fall. It is shown in particular that Al-Zr foils produced by magnetron sputtering have an attractive cold forming and hardening potential due to a microstructure consisting essentially of an oversaturated solid solution of zirconium in the aluminium matrix. This material state enables adequate formability and simplifies the heat treatment process since no solution annealing is required.

3D FEM Simulation of the Effect of Cooling Rate on SDAS and Macrosegregation of a High Strength Steel

2018 ◽  
Vol 941 ◽  
pp. 2360-2364 ◽  
Author(s):  
Gary Brionne ◽  
Abdelhalim Loucif ◽  
Chun Ping Zhang ◽  
Louis Philippe Lapierre-Boire ◽  
Mohammad Jahazi
Keyword(s):  
Boundary Conditions ◽  
Mushy Zone ◽  
Cooling Rate ◽  
High Strength Steel ◽  
Fem Simulation ◽  
High Strength ◽  
3D Fem ◽  
Cooling Rates ◽  
Positive Segregation ◽  
The Difference

Secondary dendrite arm spacing (SDAS) is a macrosegregation parameter directly linked to content of macrosegregation through cooling rates. The aim of this paper is to highlight the effect of cooling rate on the SDAS and macrosegregation patterns in a high strength steel. For this purpose, directionnal solidification in a cylinder was modeled with a plane-front solidification. Two cylinders were modeled with different boundary conditions (Tsurface = 1000°C and 1200°C). Using the FEM software Thercast, 3D macrosegregation maps were generated with thermomechanic algorithm taking into account metal shrinkage. Using Won’s equation, the influence of cooling rates in the mushy zone on SDAS was determined. The results indicated that a 72% lower difference in the area of negative macrosegregation zone (macrosegregation ratio (rseg) < -0.016%) for lower cooling rate (Ts = 1200°C). The difference of the area for positive segregation was 85% lower for higher cooling rates.

Sign in / Sign up

Export Citation Format

Share Document