Modern methods to retrieve innovative material solutions for tribosystems
A numerical, tribological data collection system with 12,100 data records was developed to find materials for tribological operations. The databse enables the user to search, retrieve and display information and data about the appropriate material couples in a fast and conventient way. The database is intended to be used by researchers, engineers, consultants and developers. All tribological characteristics of the listed materials are directly comparable; the data has been compiled and put into a standardized form, which covers the specific properties of nearly all tribometers used. The structure and the precisely defined formats may help guide future scientists and engineers to organize, archive and publish their tribological tests and results in a complete and comprehensive way.
The implementation of tribological principles in an expert-system (“PRECEPT”) for the selection of metallic materials, surface treatments and coatings in engineering design
Abstract Many of the component failures occurring in service can be avoided or delayed by better incorporation of tribological principles into engineering design. However, the concept of tribology has not yet penetrated successfully into industry in general and there remains an urgent need for the provision of practical tribology design criteria and the transference of tribology knowledge to engineering designers. Knowledge-based computer systems offer great potential for effecting tribology knowledge transfer and promoting improved design practice. Here we report the development and implementation of eight wear design rules in an expert system for assisting the selection of metallic materials, surface treatments and coatings during the initial stages of engineering design. These rules, which are intended principally for engineering designers involved with fine mechanical constructions operating at temperatures at or close to room temperature, allow the tribological reliability of a candidate design to be assessed on the basis of the most likely wear-related problems that can arise in service.
The wear of metals by relatively soft abrasives
Abstract In previous work, values were established for the relative wear resistance β of a range of metals and alloys on hard abrasive, and the maximum hardness Hu of the surface material when strained plastically. The wear of these materials is now considered on abrasives of moderate hardness, Ha, such as flint and glass, with the object of explaining their wear characteristics under abrasion in soil. It is found that the relative wear resistance b increases, compared with the value β applicable to hard abrasive, when Hu exceeds about 0.8 Ha. A secondary increase in b occurs when the hardness H of the bulk of the material exceeds about 0.8 Ha. It is concluded from this and other evidence that both metals and alloys reach a maximum hardness Hu only locally. Significant relationships between b/β and Hu/Ha or H/Ha, show that the wearing action is similar to that of hard abrasive, modified by damage to the abrasive grit. Scratching and abrasive wear cease under some conditions when the yield stress of the material slightly exceeds that of the abrasive. The increases in b/β are much larger on fine than on coarse grit abrasive. This is associated with wear and plastic flow of the fine grit and shattering of the coarse grit. For heterogeneous materials this effect is augmented due to hard particles in the metals becoming more effective when they are large compared with the scale of cutting. This compares well with results in field soils. The similarity to types of wear arising in industrial practice and classed as scratching and grinding abrasion is noted.