M. Adamiak

Properties and corrosion resistance of PM composite materials based on EN AW-Al Cu4Mg1(A) aluminium alloy reinforced with Ti(C,N) particles

The paper presents investigation results of the heat treatment effect on the properties and corrosion resistance of sintered composite materials with EN AW-Al Cu4Mg1(A) alloy matrix reinforced with Ti(C,N) particles of various volume fractions. Composite materials were examined without heat treatment and after heat treatment which was carried out to improve their properties and corrosion resistance. It was found that the proportion of reinforcement particles Ti(C,N) has an effect on the mechanical properties of composite materials. An increase in hardness and decrease in compression strength, tensile strength and abrasive wear are observed with the increase in the fraction of reinforcement particles. The corrosion susceptibility of the composite materials was determined using the potentiodynamic method in a 3% aqueous solution of NaCl. Based on the determined anode polarisation curves and also on the electrochemical parameters, the investigated materials are susceptible to pitting corrosion.

Composite Materials Based on EN AW-Al Cu4Mg1(A) Aluminum Alloy Reinforced with the Ti(C,N) Ceramic Particles

Investigations of composite materials based on EN AW-Al Cu4Mg1(A) aluminum alloy reinforced with the Ti(C,N) particles with various weight ratios of 5, 10, and 15% are presented. Powders of the starting materials were mixed in the laboratory vibratory ball mill to acquire the uniform distribution of reinforcement particles in the matrix material. The components were initially compacted at cold state in a die with the diameter of ∅ 26 mm in the laboratory vertical unidirectional press – with a capacity of 350 kN. The obtained P/M compacts were heated to a temperature of 480÷500°C and finally extruded – with the extrusion pressure of 500 kN. Bars with a diameter of 8 mm were obtained as the end product. Based on the microstructural examinations of the obtained composite materials, the uniform distribution of the reinforcing particles in the aluminum matrix was revealed. Hardness tests, tensile tests and the ultimate compressive strength tests made it possible demonstrate that all these properties change along with the reinforcing particles concentration change.

Preliminary studies on the suitability of rheocast Al alloys for deep drawing

Abstract This work analyses comparatively the behaviour of AlMg 5052 alloy sheets, in rolled and rheocast conditions, in deep drawing operations. Tensile tests and Erichsen cupping tests were performed to evaluate deformation behaviour in the two types of structures. Results showed higher deformation at lower required forces for rheocast material. Tensile test showed %EL four times higher, YS three times smaller and UTS two times smaller in the rheocast sheets compared to the rolled condition. Erichsen tests showed failure of rheocast at F max 24% smaller and total displacement 38% higher than rolled sheets. Fracture analysis showed distinct patterns, coalescence of dimples leading to fracture in rolled material, intergranular crack in rheocast. To produce the same degree of deformation, rheocast material requires 50% of the force required for rolled sheet. General results shows therefore, in terms of processing, that rheocast material can be an interesting raw material for deep drawing operations, meaning significant energy savings and formability improvement.

PVD coatings deposited onto plasma nitrided X37CrMoV5-1 type steel

The purpose of this paper was characterisation of the structure, mechanical and tribological properties of the monolayers CrN, TiN and multilayers TiN/(Ti,Al)N PVD coatings deposited onto plasma nitrided X37CrMoV5-1 type hot work tool steel. Taking into account the results of measurements, one can state that the lowest wear at certain conditions in both room and elevated temperatures displays the TiN/(Ti,Al)N multilayer coating, what can be connected with their good adherence to the substrate materials as well as the highest hardness. The investigation results will provide useful information to applying the PVD coating for the improvement of wear resistance of tools made from hot work steels. The paper contributes to better understanding of the structure, adhesion and the wear resistance at the elevated temperature up to 500°C of CrN and TiN, TiN/(Ti,Al)N PVD coatings deposition onto hot work tool steel X37CrMoV5-1 type. [Received on 25 October 2005; Accepted on 12 February 2007]

Structure and Properties of PM Composite Materials Based on EN AW-AlCu4Mg1(A) Aluminium Alloy Reinforced with the Ti(C,N) Particles

Investigations of composite materials based on EN AW-Al Cu4Mg1(A) aluminum alloy reinforced with the Ti(C,N) particles with various weight ratios of 5, 10 and 15% are presented. The metallographic examinations of composite materials show banding of the reinforcing particles in aluminum matrix after extrusion process. Structure oriented in parallel with extrusion direction is observed in composites materials. Portion of reinforcement particles Ti(C,N) has influence on the mechanical properties of composite materials. The increase of hardness, abrasive wear and decrease of compression strength, tensile strength is observed with the portion growth of reinforcement particles.

Characterization of Microstructure and Mechanical Properties of 6060 Aluminum Alloy Processed by ECAP

The purpose of this paper is to present the microstructure and mechanical behavior of 6060 aluminum alloy after intense plastic deformation. Equal Channel Angular Pressing (ECAP) was used as a method of severe plastic deformation. Before ECAP part of the samples were heat treated to remove internal stresses in the commercially available aluminium alloy. The evolution of microstructure and tensile strength were tested after 1, 3, 6 and 9 ECAP passes in annealed and non annealed states. It was found that intensely plastically deformed refined grains were present in the tested samples and exhibited increased mechanical properties. Differences were noted between samples without and after heat treatment

Properties and Structure of Deposited Nanocrystalline Coatings in Relation to Selected Construction Materials Resistant to Abrasive Wear

Presented in this work are the properties and structure characteristics of MMA (Manual Metal Arc) deposited nanocrystalline coatings (Fe-Cr-Nb-B) applied to an iron nanoalloy matrix on an S355N steel substrate in relation to selected construction materials resistant to abrasive wear currently used in industry. The obtained overlay welds were subjected to macro and microscopic metallographic examinations; grain size was determined by X-ray diffraction (XRD), and chemical composition of precipitates was determined by energy-dispersive X-ray spectroscopy (EDS) during scanning electron microscopy (SEM). The size of the crystalline grains of the Fe-Cr-Nb-B nanocrystalline microstructure was analyzed using an Xpert PRO X-ray diffractometer. Analysis of the test results of the obtained layers of arc-welded Fe-Cr-Nb-B-type alloy confirmed that the obtained layers are made of crystallites with a size of 20 nm, which classifies these layers as nanocrystalline. The obtained nanocrystalline coatings were assessed by hardness and with the use of metal-mineral abrasion testing. The results of the coatings’ properties tests were compared to HARDOX 400 alloy steel.

The causes of high power diode laser brazed seams fractures of dissimilar materials

Presented in this article are the results of experiments carried out to determine the causes of braze cracking of dissimilar materials brazed with a ROFIN DL 020 high power diode laser with the use of additional powdered EN AW-1070A aluminium alloy to bond thin aluminium sheets with soft, low alloy DC04+ZE75/75 steel plate which was electrolytically coated with zinc on both sides. Presented are the results of metallographic, macroscopic, microscopic, diffractometric phase analyses of the weld joints. Metallurgical problems arising during processing as well as suggestions regarding technical aspects of laser brazing dissimilar materials in regards to their physical characteristics and chemical composition are explored.

Microstructure and mechanical properties of the annealed 6060 aluminium alloy processed by ECAP method

Purpose: The main goal of this paper is to present the investigation results of microstructural evolution and mechanical properties changes in commercial EN AW 6060) aluminium alloy after intensive plastic deformation, obtained by equal channel angular pressing (ECAP) techniques in an annealed state. Design/methodology/approach: Annealing heat treatment was used to remove various types of internal stress in a commercially available alloy in order to increase workability of the material. The evolution of its properties and material behaviour was evaluated after 2,4,6,and 8 passes of the ECAP process. Findings: It was found that the mechanical properties and microstructure during intensive plastic deformation, such as that during the ECAP process, were changed. Plastic deformation refined grains in the aluminium alloy and increased its mechanical properties. Research limitations/implications: The presented study shows results of the investigated material in an annealed state. Practical implications: The applied processing route allows development of materials characterized by high strength and ultrafine grain microstructure compared to un-deformed annealed aluminium alloy. Originality/value: The work presents data about the influence of intensive plastic deformation on the microstructure and mechanical properties of 6060 aluminium alloy after annealing.

The influence of heat treatment on corrosion resistance of PM composite materials based on EN AW-AlCu4Mg1(A) aluminium alloy reinforced with the Ti(C,N) particles

Investigation results of the heat treatment effect on the corrosion resistance of the EN AW-AlCu4Mg1 (A) aluminium alloy base composite materials reinforced with the Ti(C,N) particles with varying volume fractions are presented. Examinations were made of the EN AW-Al Cu4Mg1(A) aluminum alloy, and also of the composite materials with the matrix from this aluminium alloy. It was found out, basing on own research, that corrosion wear after the corrosion tests of the composite materials with the addition of 5% of the Ti(C,N) particles is smaller compared to the pure aluminium alloy. Precipitation hardening causes improvement of the corrosion resistance of the investigated composite materials and - like in the state before the heat treatment, materials with 5% portion of the Ti(C,N) reinforcement ratio are characteristic of more advantageous features compared to the material without the reinforcement.