Influence Of Diverse Pore-forming Agents On The Functions Of Superfinish Grinding Tools

The superfinish grinding tool is mainly used in the producing process of highly-delicate apparatus and devices, so that the mirror-like surface of these products can be obtained in a highly efficient way. Due to the technical security between countries, it is urgent to research and develop our own products with our own intellectual property, in order to meet the ever increasing practical demand in relative areas. The technology of superfinish grinding demands not only precision in grinding but also efficiency. Some relatively good pore-forming material is one of key factors for the superfinish grinding tool to work in a highly efficient way, and it is essential and fundamental to find such a kind of material in preparing the superfinish grinding tool. Ceramic specimens with different kinds of pore-forming agents were firstly sintered in the study; and bending strength, porosity, water absorption, bulk density and SEM images of these specimens were measured and observed; and so the material with relatively good pore-forming ability was found. Effects on the factors of size, distribution, structrue of pores in the specimens were discussed and analyzed, which stemed from elements such as content, partical size, and so on. Finally, the influence from the sintering system on the product’s function and property such as bulk density and mechnical strength was studied.It is showed in study results that pore-forming agents can be classified into four groups: agents decomposing with high temperature, agents with pore structures in themselves, agents burning when heated, agents which do not react in high temperature but dissolve in some solutions at room temperature. And the agents with pore structures in themselves possess the best working ability. With the increase content of pore-forming agent, the porosity increases and pore size becomes big, yet the mechanical strength decreases. Pores will connect with each other and become bubbles if the agent content is too high, making the strength of specimens drop dramatically. The partical size of pore-forming agent should be appropriate, so that there can be many pores in the bodies of ceramic specimen, which distribute uniformly and maintain proper size. And then the superfinish grinding tool with good micro-structrue will be obtained, with ideal porosity and mechanical strength. Granules of the ceramic specimen will heavily pile up if the partical size is over fine, with the process of sintering, the pores will become smaller, leaves poor pore-forming effects. The heat processing system will also have influence on the functions of superfinish grinding tools. Porosity of the specimens will be brought up when the sintering temperature rises in certain range, and then specimen’s mechanical strength increases with the densification of sintering body. The working mechanism of pore-forming agents is easy to be destroyed if the sintering temperature is too high, leaving no products with good properties.