Liquid-phase sintering stages

Fig. 10 PLLA/HAp liquid-phase sintering stages 1-V. Reprinted from [135] with permission from Elsevier...

Densification during liquid-phase sintering occurs in tliree stages. Initially, liquid fonns at particle intersections and redistributes tliroughout the particulate mass under the influence of the capillary action. Shear stresses due to the... 

There are four stages to liquid phase sintering. 

Figure 2. Schematic diagram illustrating the three stages of liquid phase sintering, with the dominant mechanisms and processes for each stage. (After Ref 1.)...

Spreading is the process in which the liquid distributes itself to cover the surfaces of the particles. It is important in the early stage of liquid phase sintering because the liquid normally forms in isolated regions of the compact. A spreading liquid has a contact angle of zero. 

The pcD manufacturing process can be roughly divided into three stages cold compaction, hot compaction, and liquid phase sintering of the diamond compact. 

We describe hot compaction as the stage where temperature is applied together with pressure but the temperatures are not high enough to start infiltration/liquid phase sintering processes. 

The manufacturing process (especially the cold and hot compaction stages) of pcBN is very similar to that of pcD, summarized in Section 1.3.3. However, the types of binders used and liquid phase sintering mechanisms can be quite different. In pcBN production, reactive sintering plays a major role in terms of driving the densification process, whereas in pcD, dissolution and precipitation and/or adhesion/coalescence are the main driving mechanisms. A typical example for pcBN would be the following reaction [162]. 

Similarly, the mechanisms of liquid-phase sintering can be described by dividing the process into three stages. The first stage involves the redistrihulion of the liquid... 

Gessinge GH, Fischmei HF, Lukas HL (1973) Model for second-stage liquid-phase sintering with a partially wetting liquid. Acta MetaU 21 715-724... 

Two models and theories have been proposed to explain densification during liquid phase sintering. The former model, which was proposed by Caimon and Lend, suggests that liquid phase sintering consists of three stages ... 

So far, two models and theories have been developed for explaining densifi-cation during liquid phase sintering. One is the classical three-stage model and theory and the other the pore filling model and theory. ... 

The classical model and theory of liquid phase sintering asserts that liquid phase sintering can be divided into three stages ... 

Since the development of the classical model and theory, almost all of the phenomena and kinetics of liquid phase sintering have been explained and analysed in terms of the three-stage model and theory. In particular, the theory of the second stage, contact flattening theory, has been the standard theory of liquid phase sintering for decades, despite doubts raised by some research-ergi3,i5,i6,i05,i06 validity of the basic assumptions. Modified contact... 

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