scholarly journals Effects of strontium-modification and non-equilibrium eutectic melting heat treatment on the impact strength of Al-Si-Cu alloy castings.

1990 ◽  
Vol 40 (3) ◽  
pp. 188-194 ◽  
Author(s):  
Yoshihiro SHIMIZU ◽  
Yoji AWANO ◽  
Motoyuki NAKAMURA
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Eutectic Melting ◽  
Melting Heat ◽  
Cu Alloy ◽  
Alloy Castings ◽  
The Impact ◽  
Non Equilibrium

scholarly journals Effect of Soft Annealing Treatment on Impact Strength and Hardness of the EN AC-AlSi11 Alloy

2017 ◽  
Vol 17 (3) ◽  
pp. 55-58
Author(s):  
A. Jarco
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Direct Effect ◽  
Brinell Hardness ◽  
Eutectic Silicon ◽  
Annealing Treatment ◽  
Input Parameters ◽  
The Impact ◽  
Testing Plan

Abstract The paper presents research on the effects of soft annealing parameters on a change of the impact strength KC and Brinell hardness (HB) of the EN AC-AlSi11 alloy. The research has been performed according to the trivalent testing plan for two input parameters – temperature in the range between 280°C and 370°C and time in the range between 2 and 8 hours. The application of such heat treatment improves the plasticity of the investigated alloy. The improvement of the impact strength KC by 71% and the decrease of the hardness HB by 20% was achieved for the soft annealing treatment conducted at a temperature 370°C for 8 hours, compared to the alloy without the heat treatment. A change of the form of eutectic silicon precipitations which underwent refinement, coagulation and partial rounding, had a direct effect on the hardness HB and impact strength KC. The results obtained were used to prepare space plots enabling the temperature and time for soft annealing treatment to be selected with reference to the obtained impact strength KC and hardness HB of the alloy with the heat treatment.

Influence of the conditions of casting and heat treatment on the structure and mechanical properties of the AlMg10 alloy

2017 ◽  
Vol 1 (83) ◽  
pp. 26-32
Author(s):  
P. Kordas
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Liquid State ◽  
Precipitation Hardening ◽  
Solidification Rate ◽  
Dendritic Structure ◽  
Grain Structure ◽  
Alloy Castings ◽  
Die Castings ◽  
The Impact

Purpose: Assessment of the possibilities of shaping the structure and improvement of mechanical properties of casting from AlMg10 alloy through a selection of casting technology and precipitation hardening. Design/methodology/approach: the work evaluated the impact of casting and heat treatment technology on the mechanical properties and structure of AlMg10 alloy castings. The tests were performed on 200 mm × 100 mm × 25 mm plate castings produced by gravity casting methods for sand and metal moulds and by a liquid state press moulding technology. Castings made with these technologies solidify in substantially different heat- evaporation conditions and exhibit varying degrees of primary structure fragmentation. Metallographic and strength tests were performed on raw castings and after heat treatment. Findings: The changes in the morphology and size of primary crystals and the dispersion of the reinforcing phase according to the casting solidification rate and the precipitation hardening treatment were analyzed. Solidifying castings in the form of sand show a globular structure, whereas in die and press castings, a typically dendritic structure occurs, with the dendritic crystals in pressed castings being much smaller in size than the die castings. In castings which were not heat-treated, the reinforcing phase of Al3Mg2 occurs in interdendritic spaces, and its dispersion increases with the rate of cooling. After supersaturation and ageing treatments, the phase α has a grain structure in all samples. The largest dispersion of reinforcing molecules is characterized by press castings. In a raw state, the highest mechanical properties are shown by castings made in the form of sand and the method of pressing in a liquid state. Heat treatment of AlMg10 alloy castings significantly influences the increase of mechanical indexes in all castings investigated. The highest features of Rm are approx. 330 MPa and A5 above 10% is obtained in castings made by the press method. Research limitations/implications: Particular attention should be paid to the avoidance of the effects of slag inclusion, shrinkage and magnesium oxidation during casting of AlMg10 alloys. In die castings of a plate type, due to own stresses, a significant decrease in mechanical properties occurs. Practical implications: The most advantageous mechanical properties of AlMg10 alloy castings are obtained by using liquid-state pressing technology. In addition, this technology makes it possible to produce thin-walled castings of high dimensional accuracy, high air- tightness, fine grain structure, lack of surface defects and low roughness. Originality/value: The paper presents the possibility of improving the mechanical properties of AlMg10 castings by applying heat treatment. It has been proven that the casting method has a significant effect on the mechanical properties of the castings.

The Influence of Boron on Structure and Mechanical Properties of Bainite Ductile Iron in the Step Austempering in Room Temperature Machine Oil

2010 ◽  
Vol 139-141 ◽  
pp. 235-238
Author(s):  
De Qiang Wei
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Impact Strength ◽  
Ductile Iron ◽  
Room Temperature ◽  
Solute Drag ◽  
Ductile Cast Iron ◽  
Treatment Technique ◽  
The Impact

In this paper, the low alloy bainite ductile cast iron has been obtained by a new heat treatment technique of the step austempering in room-temperature machine oil. The effects of element boron, manganese and copper on structure and mechanical properties of the bainite ductile cast Iron in above-mentioned process are investigated. The phenomenon, hardness lag of the alloyed bainite ductile cast Iron, has been discussed. It shows that after the step austempering in room-temperature machine oil, the hardness will increases with the time. It is found that boron and manganese can increase the hardness and reduce the impact strength while copper can increase the impact strength. The results show that reasonable alloyed elements can improve mechanical properties of the bainite ductile cast Iron. Essentially, hardness lag of the alloyed bainite ductile cast Iron is resulted from solute drag-like effect.

Optimization of multistage artificial aging parameters on Al-Cu alloy mechanical properties

2018 ◽  
Vol 2 (87) ◽  
pp. 62-67
Author(s):  
D.I. Tsamroh ◽  
P. Puspitasari ◽  
A. Andoko ◽  
A.A. Permanasari ◽  
P.E. Setyawan
Keyword(s):  
Heat Treatment ◽  
Artificial Aging ◽  
Research Result ◽  
Aging Treatment ◽  
Optimal Level ◽  
Holding Time ◽  
Design Parameters ◽  
Aging Research ◽  
Cu Alloy ◽  
The Impact

Purpose: This research is aimed to describe heat treatment process by using multistage artificial aging for Al-Cu alloy with Taguchi method in Minitab 16 to optimize the heat treatment parameters. This research conducted due to the applied of aluminium alloy in automotive industrial and aircraft industrial that has good properties for fabrication. Design/methodology/approach: Methodology that use in this paper is experimental design with statistical approach. Three controllable parameters were selected, they were temperature aging, holding time of aging, and the number of stages. The hardness value and impact value after multistage artificial aging were chosen as quality characteristics. The experiment was performed using orthogonal arrays of L9 (33). Findings: The finding that resulted in this research are the most significant parameters that affected hardness and toughness value of Al-Cu alloy against multistage artificial aging. The optimal hardness and toughness for Al-Cu alloy were obtained with heat treatment at temperature 200ºC, holding time for 6 hours, with two stages artificial aging. Research limitations/implications: The limitation that found in this research is even optimal level had been determined, it is unable to determine the true optimal value of each design parameters. Practical implications: This optimization process can be applied in manufacture process in industrial without spend expensive cost and time. Originality/value: According to research result, can be understood that by conducting these experiments, the impact value and the hardness value of Al-Cu alloy increase with multistage artificial aging treatment.

Influence of heat treatment on the impact strength of 40Kn steel

1984 ◽  
Vol 16 (4) ◽  
pp. 496-499
Author(s):  
V. K. Golubev ◽  
S. A. Novikov ◽  
Yu. S. Sobolev ◽  
H. A. Yukina
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
The Impact

The Causes of Low Impact Strength of T23 Steel Weld Joints

2015 ◽  
Vol 226 ◽  
pp. 103-106
Author(s):  
Janusz Adamiec ◽  
Izabela Pikos ◽  
Michał Stopyra
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Weld Metal ◽  
Post Weld Heat Treatment ◽  
Weld Joints ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
The Impact ◽  
Welding Technique ◽  
Weld Heat

T23 is modern bainitic steel designed for use in supercritical boilers. According to producer’s data weldability of this steel is good enough to avoid post-weld heat treatment. However, some of the T23 weld joints in as-welded condition have not met the minimal ductility requirement. The impact test revealed significant differences between the joints in as-welded and heat treated condition. Metallographic and fractographic examinations have been conducted in order to explain those differences. The specimens with low impact strength were characterized by brittle fracture and non-tempered martensite presence in weld metal. It was concluded that avoiding formation of disadvantageous structure in weld metal requires conducting of post weld heat treatment or applying multi-pass welding technique with annealing run.

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