Computer aided method for evaluation of failure class of materials working in creep conditions

One of the innovative technology of producing the components is Selective Laser Melting (SLM) belongs to additive manufacturing techniques. SLM technology has already been successfully applied in the automotive, aerospace and medical industries. Despite progress in material flexibility and mechanical performances, relatively poor surface finish still presents a significant weakness in the SLM process. The scope of the present article is the study the influence of selective laser melting parameters such as laser power, scanning speed, exposure time and hatch spacing through additive manufacturing as well as the orientation of the model corresponding to the laser beam on the surface characteristic of the components made from Ti-6Al-4V alloy. By using optimized process parameters, a low surface roughness can be obtained. In research, the machine for the selective laser melting of metal powders Renishaw AM 125 device was used. Based on experiment plan, 32 models were produced, which were examined to define the surface roughness and thus represent an influence of process parameters and the orientation on the model surface quality. The article discusses the fundamental factors determining the roughness that gives invaluable knowledge to improve the surface quality of SLM parts.

Section: Surface Quality Research For Selective Laser Melting Of Ti-6mentioning

confidence: 99%

Section: Surface Quality Research For Selective Laser Melting Of Ti-6mentioning

confidence: 99%

Surface Quality Research for Selective Laser Melting of Ti-6Al-4V Alloy

Król¹,

Tański²

2016

“…Then the high potential of this method to modify the surface properties of titanium and titanium alloys was recognized [3,[39][40][41][42]. The first trials of laser gas nitriding (LGN) of pure titanium were carried out by the available at that time gas CO 2 laser, which provided a high enough level of output laser power.…”

Section: Introductionmentioning

confidence: 99%

Comparison of Titanium Metal Matrix Composite Surface Layers Produced During Laser Gas Nitriding of Ti6Al4V Alloy by Different Types of Lasers

Lisiecki¹

2016

The article presents the results of a comparative study of the nitriding process of titanium alloy substrate using two lasers with different characteristics of laser beams. One of the applied lasers was a high power diode laser emitting at a dominant wavelength of 808 nm, with a rectangular laser beam spot, and multimode energy distribution across the spot. The second laser was a solid state Yb:YAG disk laser emitting at a wavelength of 1.03 µm, with a circular beam spot, characterized by near Gaussian energy distribution across the spot. In a case of both lasers single stringer beads with a similar width and at similar energy input were produced. As a result of melting of the substrate with a laser beam in a pure gaseous nitrogen atmosphere composite surface layers with in situ precipitated titanium nitrides embedded in the metallic matrix of titanium alloy were produced, in both cases. However, the surface topography and structure is different for the surface layers produce by different lasers at the same processing parameters and width of laser beams.

“…The appropriately selected chemical composition of steel and the appropriately selected technological process allow to achieve a structure and a set of strength and plastic properties of steel, as illustrated by indicators equal to tensile strength multiplied by maximum elongation (the field under the curve -an integral of stress variations in the function of deformation is a measure of cracking ductility), whilst relatively high strain energy per unit volume ensures energy absorption and prevents premature fracture of the damaged car components. The intensive mechanical twinning mechanisms induced in high manganese austenitic steels, ensuring an increased reserve of energy unprecedented for other steels, allows to shapen technologically parts with a complicated shape and to unload energy during plastic deformation at high rates, in particular during a road accident [1][2][3][4][5][6][7][19][20][21]. The modern quality requirements for automotive vehicles and other means of transport relate primarily to implementation of programmes improving the passive safety of traffic users, to possibly lowest weight of vehicles and to the resulting reduction in fuel consumption and in the related emission of fumes into the air, as well as to comfort, aesthetics and many other aspects.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties of High-Mn Austenitic Steel Tested under Static and Dynamic Conditions

Dobrzański

Borek

Mazurkiewicz

2016

MechanIcal propertIes of hIgh-Mn austenItIc steel tested under statIc and dynaMIc condItIonsThe purpose of the paper is to investigate X73MnsiAlNbTi25-1-3 high manganese austenitic steel containing 0.73% c to determine structural mechanisms decisive for increasing a reserve of cold deformation energy of such steel. The influence of a strain rate on the structure of the investigated steels and on the structural mechanisms decisive for their properties was analysed. Specialist research instrumentation was used for this purpose such as Scanning Transmission Microscopy (including EBSD examinations), conventional and high-resolution transmission electron microscopy together with diffraction examinations and metallographic examinations. It was found that the principal cause of an increased reserve of cold deformation energy of the investigated steels in dynamic conditions is the activation of mechanical twinning in the mutually intersecting systems in austenite grains and annealing twins, which are densifying when a cold deformation rate is growing, thereby confirming the basic mechanism of TWiP (TWinning induced Plasticity).