HIP diagrams

The various densification mechanisms at different temperatures can be modelled and displayed in HIP diagrams, in which relative temperature is plotted against temperature normalised with respect to the melting-point (Arzt el al. 1983). This procedure relates closely to the deformation-mechanism maps discussed in Section 5.1.2.2. 

Figure 5.9 shows an example of HIP diagrams which identify the dominant densification mechanism under various experimental conditions and shows the rate of densification that results from all the mechanisms acting together. As can be seen in the diagrams, diffusion is usually the dominant mechanism in ceramics even under a high external pressure while power-law creep can be an important densification mechanism in metals. 

Figure 5.9. Examples of HIP diagrams (a) density/pressure mapT = 1473 K for alumina with a particle diameter of 2.5pm, (b) density/temperature map at Pappi. = 100 MN/m for alumina with a particle diameter of 2.5 pm and, (c) density/pressure map at T = 1473K for a superalloy with a particle diameter of 50 pm. ...

Figure 15.1.1 A schematic diagram of the two components of an artificial hip the stem or femoral component and the socket or acetabular component.

When the powder is isostatically compacted at elevated temperatnres, the process is called hot isostatic pressing (HIP). In this case, the flexible dies are often made of thin metals, and high-pressnre gases snch as argon are nsed to heat the part rapidly and rednce thermal losses. Pressnre np to 100 MPa and temperatnres in excess of 2000°C are possible nsing HIP, and parts up to 600 kg can be fabricated. A schematic diagram of a typical HIP apparatus is shown in Figure 7.18. Metals that are processed commercially by HIP include various specialty steels, superalloys, hard metals, refractory alloys, and beryllium. We will see in Section 7.2 that HIP is also particularly useful for the densification of ceramic components. 

Figure 7.18 Schematic diagram of a hot isostatic pressing (HIP) operation. Reprinted, by permission, from Encyclopedia of Materials Science Engineering, Vol. 3, p. 2188. Copyright 1986 by Pergamon Press.

Figure 9.31 Chromatograms obtained from various samples incubated with (upper diagram) or without (lower diagram) Hip-His-Leu (HHL). (A) Standard mixture of 2.7 nmol His-Leu, 2.7 nmol hippuric acid, and 100 nmol Hip-His-Leu. (B) A 50 /xL aliquot of serum or (C) whole blood was incubated with or without 5 mM Hip-His-Leu. After 30 minutes, 0.7S mL of 3% m-phosphoric acid was added and centrifuged. (D) Lung or (E) kidney was homogenized in S volumes of chilled Tris-HCl buffer containing 0.5% Nonidet-P40, and centrifuged. The supernatant was incubated with or without 5 mAf Hip-His-Leu. In the case of lung, the supernatant was diluted 20 times with the buffer prior to incubation with Hip-His-Leu. Peaks 1, His-Leu 2, hippuric acid 3, Hip-His-Leu. (From Horiuchi et al., 1982.)...

It has been shown that fracture is a very complex process and the fracture performance depends on both the initiation and the propagation of a defect [6-10] in the material. Under impact, most polymers break in very distinct manners. Several types of fracture have been identified depending on the amount of plastic deformation at the crack tip and the stability of crack propagation. For each type, an appropriate analysis has been developed to determine the impact fracture energy of the material. These methods have also been verified in various plastics [11,12]. The different fracture behaviors in most polymers are illustrated in Figure 27.1, which shows a schematic drawing of the load-deflection diagram of Charpy tests on HIPS [13] under an impact velocity of 2 m/s at various temperatures. 

Figure 27.1 Load-deflection diagram of Charpy tests on HIPS at 2 m/s...

Further increase in the concentration of the epoxy resin polymer will lead to a phase inversion within the CTBN phase. The nodules in the scanning electron microscopy images are of the phase separated epoxy phase (Figure 8.6). This behaviour has striking similarities to the HIPS system and the phase diagrams for this relatively polar system are strikingly similar to those of HIPS. 

Figure 16.1. Diagram of loose total hip joint with periprotheticos...

The TTT Cure Diagram Evidence to date suggests that interpenetrating polymer networks, like most polymer blends, exhibit lower critical solution temperatures (42). However, the development of morphology with polymerization of one or more of its components is complicated by the presence of cross-linking. Thus the materials cannot be stirred beyond a certain point, as can the HIPS materials, and cannot be made to fiow at elevated temperatures they are thermoset materials. 

A flow diagram of the HIPS process is shown in Figure 4.5. 

Figure 4.5 Flow diagram showing the HIPS process 4.2.3.2 Technical parameters...

Osteoporosis is a major public problem, it is a skeletal disease characterized by low bone mass and microarchitec-tural deterioration. Osteoporotic patient occur fragility fracture frequently, and the common positions were vertebral, hip, wrist. There was 1.66million hip fracture in worldwide [1], 1,197,000 in women and 463,000 in men. Dynamic hip screw was the standard treatment in stable femoral proximal fracture. But in unstable fracture, it has high failure rate. Unstable fracture has the weak structure, it cause that the force loads on femoral head. Then the cut-out complication will happen, especially on osteoporotic patient. The hip biomechanics can help us to design new device and develop new technique to solve the clinical problem. From the diagram of the lines of stress in the upper femur, the lesser trochanter supply the compression... 

Figure 5 Orbital contour diagrams for acetaldehyde non-orthogonal Cme-Hip bonding and C-Haid antibonding pre-NBOs (6-31G(d,p)), illustrating the more favorable overlap (designated by shaded areas) for the equilibrium conformation. The contours are taken in the skeletal plane. Outermost contour is at 0.03 with each inner contour increasing by 0.01...

Figure 8 Depiction of major factors contributing to propene internal rotation barrier, Cme-Csec bond weakening, designated in red Cme-Hip bond and Csec-H antibond interaction, designated in green. Contour diagrams are as in Figure 5...

Phase Diagram for PE in Hip Arthroplasty 19.5 High-pressure Crystallization... 

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