Formation of Lead Bearing Surface Layers on Aluminum Alloys by Laser Alloying

Abstract

The aim of the present work is to investigate the microstructure of Al-Pb monotectic surface layers generated by a laser surface alloying technique on the surface of an Al-4Cu-1.5Si-0.5Mg alloy. Monotectic alloys are generally used as materials for sliding bearings. Layers of a monotectic alloy generated by laser surface alloying have a potential for superior properties, because the rapid solidification during this process results in fine precipitation structures which can act as solid lubricant. The structure of the Al-Pb monotectic surface layers was observed in the light microscope and the scanning electron microscope. Volume fraction and size distribution of lead particles were determined by quantitative image analysis. Pin-on-disc experiments were carried out to characterize and compare the tribological properties of the Al-Pb monotecitc layers and cast Al-Cu-Si-Mg alloys.

Classification of laser beam induced surface engineering technologies andin situsynthesis of steel matrix surface nanocomposites

“…[76][77][78][80][81][82][83][85][86][87]91,93,94 A new wire-dosing technique (route A1-B3) has been developed by Buza and colleagues. 101,102 Using this technique, different routes can be realised: A1-B3-C4 101 or A1-B3-C5. 102 This paper will describe the possibilities of the in situ LMI technology to improve a surface of a cheap carbon tool steel substrate.…”

In-situ synthesis of a carbide reinforced steel matrix surface nanocomposite by laser melt injection technology and subsequent heat treatment

“…During LMI hard particles with the size range of 10-100 µm are blown by a gas stream into a liquid metallic pool, melted by a fast moving laser beam. The particles are usually carbides [1,[8][9][10][11][12]14,[18][19][20][21][23][24][25][26][27][29][30][31][32][33][34][35][36][38][39][40][41][42][43], borides [3][4][5][6][7], nitrides [2], oxides [13,15]), or even soft Pb droplets [28].…”

“…Laser Melt Injection (LMI) technology has been known since the 1980s [1] and has been used to improve surface characteristics of metallic alloys, such as steels [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], aluminum [18][19][20][21][22][23][24][25][26][27][28], titanium [27,[29][30][31][32][33][34][35][36][37][38][39], nickel [40][41][42] and magnesium [43]. During LMI hard particles with the size range of 10-100 µm are blown by a gas stream into a liquid metallic pool, melted by a fast moving laser beam.…”

A New Class of Engineering Materials: Particle-Stabilized Metallic Emulsions and Monotectic Alloys

“…[1] However, once the droplets are nucleated, they immediately approach each other and coalesce under the influence of gravity or the interfacial gradient force, making the production of monotectic alloys with homogeneously distributed second phase almost impossible, especially for thick castings with considerable cooling times. [2][3][4][5][6] Here, we show for the first time that solid particles with appropriate wettability can be used to stabilize liquid metallic emulsions, opening a principally new route to produce thick wall monotectic alloys with homogeneously distributed second-phase droplets (particles).There has been common knowledge in colloid chemistry for more than a century [7] regarding how to stabilize water-or oil-based liquid foams [8][9][10][11][12][13][14][15][16][17] and emulsions [13,[18][19][20][21][22] by solid particles. On the other hand, solid particle-stabilized metallic foams [23][24][25][26][27][28] were originally discovered quite empirically by metallurgists and independently from the aforedescribed common knowledge of colloid chemists.…”

“…[1] However, once the droplets are nucleated, they immediately approach each other and coalesce under the influence of gravity or the interfacial gradient force, making the production of monotectic alloys with homogeneously distributed second phase almost impossible, especially for thick castings with considerable cooling times. [2][3][4][5][6] Here, we show for the first time that solid particles with appropriate wettability can be used to stabilize liquid metallic emulsions, opening a principally new route to produce thick wall monotectic alloys with homogeneously distributed second-phase droplets (particles).…”