Kazimierz Zaleski

Edge states after wire brushing of magnesium alloys

Purpose – The purpose of the article is to investigate the influence of deburring by wire brushing upon states of magnesium alloy edges. Design/methodology/approach – AZ91HP and AZ31 magnesium alloy samples were machined with the use of recommended, catalog milling parameters. Burrs formed at the edges after milling were removed by brushing. Three different kinds of brushes were tested. Edge states (values of edge radius) after wire brushing were specified. Surface roughness was measured near the brushed edges. Findings – Experimental results show that wire brushing is an efficient deburring method, which can be fully automated on machining centers. Depending on the requirements, specific values of edge radius as well as surface roughness may be obtained. Practical implications – The article will help technological process designers select tools for deburring after milling of magnesium alloys. Originality/value – The paper presents the automated deburring method which can provide the required edge radius ...

Effect of brushing parameters upon edge states after wire brushing of AZ91 HP magnesium alloy

When the tool leaves the part during machining operations, burrs can form as a result of material plastic flow. Wire brushing is one of burr removing methods. Low cost of brushes which can be mounted in a milling center gives the perspective of developing this method. The article was aimed at presenting the results of brushing process upon edge radius after wire brushing of AZ91HP magnesium alloy. Three kinds of brushes were tested with different types of fibers and the diameter of a single fiber. Brass and steel brushes were used.

THE EFFECT OF THE ALUMINIUM ALLOY SURFACE ROUGHNESS ON THE RESTITUTION COEFFICIENT

The paper presents the results of research on the effect of the surface roughness of aluminum alloy on its coefficient of restitution. It describes the current method of finishing the workpiece surface layer after cutting and innovative measuring device which was used in the research. The material used in the research was aluminium alloy EN AW 7075. The paper also presents a relationship between the coefficient of restitution and surface roughness of the milled samples as well as impressions left by bead in function of velocity and a sample surface roughness.

THE EFFECT OF THE CONDITIONS OF SHOT PEENING THE INCONEL 718 NICKEL ALLOY ON THE GEOMETRICAL STRUCTURE OF THE SURFACE

This article presents the research results of roughness and topography of the surface of Inconel 718 nickel alloy after shot peening. The evaluation of stereometric properties of the surface layer of the examined material was performed based on the amplitude, height and Abbott-Firestone curve parameters. The shot peening was carried out on the impulse shot peening stand. The impact energy Ez, distance between the traces xs and the ball diameter dk were changed in the range: Ez = 60 ÷ 240 mJ, xs = 0,15 ÷ 0,5 mm, dk = 3,95 ÷ 12,45 mm. The T8000 RC 120-140 device of the Hommel-Etamic company, along with the software, was used for measuring the surface roughness and for determining the material bearing curve. As a result of the machining, the surface roughness was reduced and the selected functional parameters were improved.

Dynamic Diameter Determination of Circular Brushes

After milling process burrs can form as a result of plastic deformation of the material. Wire brushing can be used as a fully automated method of deburring on machining centres. In order to provide the same effects after brush change it is important to precisely determine the tool diameter. The article presents the method of dynamic diameter determination of circular brushes, which is the diameter of the brush during rotation.

EVALUATION OF THE EFFECTIVENESS OF THE SHOT PEENING PROCESS FOR THIN-WALLED PARTS BASED ON THE DIAMETER OF IMPRESSIONS PRODUCED BY THE IMPACT OF SHOT MEDIA

The paper presents the results of studies on the effectiveness of the shot peening process for thin-walled parts based on the diameter of impressions produced by the impact of shot media. It is also described the current applications of this treatment for the thin-walled parts. The authors described an innovative measuring device which was used in the research. The material used in the studies was non-alloy steel C45. The relationships between beads diameter and thickness of workpieces on diameter of impression were presented.

EFFECT OF VIBRATION SHOT PEENING PARAMETERS UPON SHAPES OF BEARING CURVES OF ALLOY STEEL SURFACE

The article presents the results of studies on the effect of technological parameters of vibration shot peening upon the shape of bearing curves and the parameters of that curve. The topography of surface formed in result of vibration shot peening and pre-machining, which was grinding, were analyzed. The material used in the studies was alloy steel 30HGSA. The shot peening process was performed on an appliance equipped with a kinematic vibrator. Shot peening time t, vibrator oscillations (vibrations) frequency ν, as well as vibrator oscillations amplitude A were changed within: t = 1–15 min, ν = 17,5–35 Hz, A = 10,3–17,3 mm. For measuring surface roughness and determining the bearing curve the appliance T8000 RC120-400 by HommelEtamic was used together with the software. In result of the machining performed surface roughness decreased, and the parameters of bearing curve improved.

Influence of the cutting parameters on the selected machinability indicators in the milling of steel EZ6NCT25

The paper reports results of an investigation of the cutting torque and surface roughness in the face milling of EZ6NCT25 steel. Classified as stainless steel, EZ6NCT25 is effectively used in the aviation and shipbuilding industries. This steel grade is used for producing elements such as turbine blades and combustion chamber assemblies. Experimental tests were performed with the use of full-carbide monolithic tools with the diameter of d = 12 mm. The tests were conducted at variable technological parameters. It has been observed that that cutting torque and amplitude cutting torque depend on machining conditions, and also, although to a lesser extent the surface roughness.

Analysis of deburring effectiveness and surface layer properties around edges of workpieces made of 7075 aluminium alloy

Purpose This paper aims to present a comprehensive analysis of deburring effectiveness and surface layer properties after deburring process by wire brushing from milled 7075 aluminium alloys objects. Edge states (rounding, chamfering), surface roughness around the edge, microhardness and residual stress distribution were analyzed. Design/methodology/approach During the machining process, undesirable phenomenon occurs, which is the formation of burrs at the edges of workpieces. They occur in most elements formed by machining. There are many methods that can be used for deburring, but in the case of large components, typical of aerospace industry, using certain methods becomes difficult or uneconomic. Taking advantage of the fact that a part is mounted on the machine, it is advisable to make deburring operation the last action. This operation can be carried out by wire brushing. Findings On the basis of conducted studies, it was demonstrated that it was possible to choose such technological brushing conditions as to ensure an effective process of deburring, form appropriate edge state and generate the desired surface layer properties. Practical implications The method presented in the article allows for efficient, automatic deburring, especially for large components made of 7075 aluminium alloy. This eliminates manual, time-consuming methods of removing burrs by locksmiths. Moreover, the results allow to evaluate changes occurring in the surface layer after brushing process. Originality/value Results of brushing experiment provide full information on selection of technological parameters to obtain the required surface roughness and edge state. Moreover, analysis of surface layer properties (microhardness, residual stress) allows to assess the degree of impact hitting fibre on the workpiece.

The Numerical FEM Model of the Kinematics of the Vibratory Shot Peening Process

The paper presents the results of numerical calculations, with the finite element method in the ABAQUS program environment, of the vibratory shot peening process with loose peening elements. The behaviour of shot peening elements was analysed in the kinematic aspect. The impact of the initial deployment of vibratory shot peening elements on their behaviour during processing was investigated, including the displacement, velocity, acceleration and the number of collisions. The way of determining the effectiveness of the processing with the vibratory shot peening was illustrated.