Effect of Liquid Hot Isostatic Pressing on Structure and Mechanical Properties of an Aluminum Alloy

2014 ◽  
Vol 794-796 ◽  
pp. 845-850 ◽  
Author(s):  
Damir Tagirov ◽  
Vladislav Kulitskiy ◽  
Nikolay Belov ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Endurance Limit ◽  
Hot Isostatic Pressing ◽  
High Strength ◽  
Shrinkage Porosity ◽  
Eutectic Phase ◽  
Isostatic Pressing ◽  
Elongation To Failure ◽  
Average Size ◽  
Brittle Intergranular Fracture

The effect of liquid hot isostatic pressing (LHIP) on microstructure and mechanical properties of a high-strength cast Al-6Zn-2Mg-0.5Fe-0.7Ni alloy was examined. LHIP eliminates shrinkage porosity that highly improves strength and fatigue limit. Yield stress (YS) and ultimate tensile strength (UTS) in T6 condition increased from 135 to 470 MPa and from 410 to 510 MPa, respectively. Endurance limit on the base of 107 cycles increased from 95 to 140 MPa. However, a small number of gas pores with an average size less than 2 μm retains. LHIP suppresses the crack initiation on coarse cavities. However, brittle intergranular fracture occurs in the hipped alloy through the breaking of eutectic phase Al9FeNi. As a result, elongation-to-failure was of 1.2% and the fatigue strength is equal to one of AA356.02 alloy subjected to LHIP.

Effect of Liquid Hot Isostatic Pressing on Structure and Mechanical Properties of Aluminum Gravity Die Castings

2012 ◽  
Vol 706-709 ◽  
pp. 408-413
Author(s):  
Elena Ivanova ◽  
Damir Tagirov ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Crack Initiation ◽  
Hot Isostatic Pressing ◽  
Fatigue Crack Initiation ◽  
Total Elongation ◽  
Shrinkage Porosity ◽  
Aluminum Casting ◽  
Isostatic Pressing ◽  
Fatigue Data ◽  
Die Castings

Effect of liquid hot isostatic pressing (LHIP) on structure and mechanical properties of an A356.0 alloy was examined. Samples from this alloy were produced by gravity die castings. Part of these samples was subjected to homogenization annealing, and the other part was subjected to LHIP following homogenization annealing. All samples were water quenched from the temperature of prior homogenization annealing or LHIP and finally aged. It was shown that the LHIP processing leads to increase in yield stress, ultimate stress and total elongation. A significant increase in fatigue strength and decreased the scattering of fatigue data takes place too. This is caused by the fact that the fatigue crack initiation mostly occurs on lateral surfaces of the samples subjected to LHIP, whereas shrinkage voids in the non-hipped condition play a major role in crack initiation. In addition, crack propagation under fatigue occurs in samples subjected to LHIP in essentially ductile manner. Thus, LHIP eliminating shrinkage porosity enhances significantly mechanical properties and reliability of aluminum casting.

scholarly journals Novel Tensile Test Jig and Mechanical Properties of WC-Co Synthesized by SHIP and HIP Process

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 884
Author(s):  
A-Ra Jo ◽  
Ji-Seob An ◽  
Sun-Hyung Kim ◽  
Myeong-Sik Jeong ◽  
Young-Hoon Moon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Tensile Testing ◽  
Hot Isostatic Pressing ◽  
High Strength ◽  
Tensile Tests ◽  
Isostatic Pressing ◽  
Manufacturing Method ◽  
Axial Tensile ◽  
Co Alloys

Tungsten carbide-cobalt (WC-Co) alloys have various mechanical properties according to their Co content and manufacturing method. High-strength materials such as WC-Co alloys are usually manufactured using various sintering methods. In this study, WC-Co was compared according to the Co content and manufacturing method using the sinter-hot isostatic pressing process. Furthermore, an additional test was performed to investigate the effect of post-hot isostatic pressing (HIP) treatment on the mechanical properties. To compare tensile strength, threaded end and shoulder end specimens are generally applied in axial tensile testing with hard metals. However, it is extremely difficult to shape WC-Co by machining. A tensile testing jig for a shoulder end specimen is, therefore, proposed. Tensile tests were conducted using the proposed jig, and microstructure, hardness, and impact tests were carried out to compare the mechanical properties. The microstructure evolution was obtained by decreasing the Co content and applying the HIP treatment, resulting in changes in Young’s modulus and strength. The results indicated that the proposed jig of the axial tensile test could be applied to the extremely hard WC-Co, and the mechanical properties of WC-Co could be modified by the Co content and HIP treatment control.

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