Measurements of the active surface microgeometry of the grinding wheel by contact and optical methods are commonly used to obtain a cloud of points representing the surface of the examined tool. Parameters that can be determined on the basis of the above-mentioned measurements can be universal parameters, which are commonly used to assess the geometric structure of a surface or parameters taking into account specific properties of the grinding wheel active surface (GWAS) structure. This article proposes a methodology for determining the average level of binder, which allows the definition the cut-off level required to separate from the measurement data: (i) the areas representing grains, (ii) the areas of gumming up of the grinding wheel, and (iii) deep cavities in approximately the same places on the investigated grinding wheel, regardless of the degree of its wear. This, in turn, allows one to track changes in characteristic parameters computed from measurements of texture in the above-mentioned areas due to different GWAS wear processes. The research was based on the analysis of data obtained from measurements of single-layer grinding wheels using the replica technique. The adopted measurement methodology enables measurement of approximately the same (94% coverage) areas of the GWAS at four stages of grinding wheel operation. Errors that were computed related to the determination of the volume of abrasive on the GWAS at various stages of wear using the developed methodology were lower, on average, by 48% compared to the automatic recognition of islands made with a commercial software.

The paper presents a method of forecasting the product surface topography after five-axis machining with a lens-shaped end-mill. Surface roughness is one of the key parameters considered when assessing the effectiveness of the machining process, especially in the aviation, automotive, tooling and medical equipment industries. The developed method, the first published, presented in the paper is based on the analytical equations of the trajectory of the cutting edge motion, on the basis of which the cutter action surface is generated. The developed model takes into account: cutting depth, cutting width, feed, lead angle and radial runout. Experimental studies were conducted using three different materials: 40HM steel, Al7035 aluminum alloy and Ti Grade 5 titanium alloy. Various values of the cutting width parameters and different feeds were used in the tests. Based on the results of the experimental tests, an empirical model (response surface model) was determined and was then used to verify the simulation model. The simulation results and the results of experimental tests were compared and conclusions were drawn regarding the developed models. The developed models supported by numerical simulation can be used to approximately estimate the influence of the width of cut $b_r$ and feed $f_t$ on selected height characteristics $S_a$ and $\widehat{Sz}$ of the geometric structure of the surface (GSS) after machining with a lens-shaped end-mill in terms of the process parameters adopted in the tests. It was found that the influence of the $f_t$ on the $S_a$ and $\widehat{Sz}$ is greater for small values of $b_r$. The effect of $b_r$ is greater with lower $f_t$ values. The cutting width $b_r$ has the greatest influence on $S_a$ and $\widehat{Sz}$, and $f_t$ and the interaction of these parameters has the least influence.

Additive processes allow for almost any manufacturing of screw-threaded joint elements. However, this requires knowledge of the geometrical relationships of a threaded itself and the strength of materials from which the screw-threaded joint is made. Thanks to the development of research...

Fatigue life of titanium and titanium alloys is frequently reduced if the load holds at the maximum stress are introduced, which is termed dwell debit. Many factors affect dwell fatigue of titanium alloys, like stress state, level and ratio, alloy chemistry, microstructure and microtexture, holding time and temperature. Dwell sensitivity of titanium alloys is usually attributed to the phenomenon of load shedding, which is a time-dependent redistribution of stress from so-called ‘weak’ to ‘strong’ grains possessing different crystallographic orientations. Stress concentration leads to crack initiation and formation of quasi-cleavage facets in ‘strong’ grains. Another factor contributing to dwell sensitivity of titanium alloys is time dependent strain accumulation, which is observed even at room temperature. In the paper, the effect of load holds and volume fraction of primary α phase on the fatigue behavior of Ti-6Al-4V alloy at the temperature of 150°C was investigated. Two variants of bi-modal microstructure of the alloy were obtained by means of the heat treatment. Stress controlled fatigue tests with and without hold time at maximum load and constant load creep test were carried out.