In the laser treatment of a workpiece (9), e.g. for surface hardening, melting, alloying, cladding, welding or cutting, the adverse effect of reflectivity of the surface, when a pure, monochromatic laser (6) is used, is remedied by the simultaneous application of a relatively shorter wavelength beam (1). The two beams (1)(5) may be combined by a beam coupler (4) or may reach the workpiece (9) by separate optical paths (not shown). The shorter wavelength beam (1) improves the coupling efficiency of the higher- powered laser beam (5).

Laser Material Processing

Sources and properties of non-exhaust particulate matter from road traffic: a review.

Calculations of the impact of friction and wear on energy consumption, economic expenditure, and CO2 emissions are presented on a global scale. This impact study covers the four main energy consuming sectors: transportation, manufacturing, power generation, and residential. Previously published four case studies on passenger cars, trucks and buses, paper machines and the mining industry were included in our detailed calculations as reference data in our current analyses. The following can be concluded:

 Fifty years ago, wear and wear-related failures were a major concern for UK industry and their mitigation was considered to be the major contributor to potential economic savings by as much as 95% in ten years by the development and deployment of new tribological solutions. The corresponding estimated savings are today still of the same orders but the calculated contribution to cost reduction is about 74% by friction reduction and to 26% from better wear protection. Overall, wear appears to be more critical than friction as it may result in catastrophic failures and operational breakdowns that can adversely impact productivity and hence cost.

/pdf/influence-of-tribology-on-global-energy-consumption-costs-pgu0i0z95u.pdf

Influence of tribology on global energy consumption, costs and emissions

A lubricating oil composition formulated with a viscosity index (VI) improver composition including a combination of an ethylene α-olefin copolymer having no greater than 66 mass % of units derived from ethylene, and a linear diblock copolymer including at least one block derived primarily from a vinyl aromatic hydrocarbon monomer, and at least one block derived primarily from diene monomer.

Lubricating oil compositions.

https://research.birmingham.ac.uk/portal/files/11961623/Estimation_of_the_Contribution_of_Road_Traffic_Emissions_V3_PostPrint.pdf

Estimation of the contribution of road traffic emissions to particulate matter concentrations from field measurements: A review

Vegetable oil-based lubricants—A review of oxidation

New plating techniques, such as non-contact plates, have been introduced in acknowledgment of the importance of biological factors in internal fixation. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability, e.g. fracture motion, and the risk of implant failure can best be controlled. The results of a study based on in vitro experiments with composite bone cylinders and finite element analysis using the Locking Compression Plate (LCP) for diaphyseal fractures are presented and recommendations for clinical practice are given. Several factors were shown to influence stability both in compression and torsion. Axial stiffness and torsional rigidity was mainly influenced by the working length, e.g. the distance of the first screw to the fracture site. By omitting one screw hole on either side of the fracture, the construct became almost twice as flexible in both compression and torsion. The number of screws also significantly affected the stability, however, more than three screws per fragment did little to increase axial stiffness; nor did four screws increase torsional rigidity. The position of the third screw in the fragment significantly affected axial stiffness, but not torsional rigidity. The closer an additional screw is positioned towards the fracture gap, the stiffer the construct becomes under compression. The rigidity under torsional load was determined by the number of screws only. Another factor affecting construct stability was the distance of the plate to the bone. Increasing this distance resulted in decreased construct stability. Finally, a shorter plate with an equal number of screws caused a reduction in axial stiffness but not in torsional rigidity. Static compression tests showed that increasing the working length, e.g. omitting the screws immediately adjacent to the fracture on both sides, significantly diminished the load causing plastic deformation of the plate. If bone contact was not present at the fracture site due to comminution, a greater working length also led to earlier failure in dynamic loading tests. For simple fractures with a small fracture gap and bone contact under dynamic load, the number of cycles until failure was greater than one million for all tested constructs. Plate failures invariably occurred through the DCP hole where the highest von Mises stresses were found in the finite element analysis (FEA). This stress was reduced in constructions with bone contact by increasing the bridging length. On the other hand, additional screws increased the implant stress since higher loads were needed to achieve bone contact. Based on the present results, the following clinical recommendations can be made for the locked internal fixator in bridging technique as part of a minimally invasive percutaneous osteosynthesis (MIPO): for fractures of the lower extremity, two or three screws on either side of the fracture should be sufficient. For fractures of the humerus or forearm, three to four screws on either side should be used as rotational forces predominate in these bones. In simple fractures with a small interfragmentary gap, one or two holes should be omitted on each side of the fracture to initiate spontaneous fracture healing, including the generation of callus formations. In fractures with a large fracture gap such as comminuted fractures, we advise placement of the innermost screws as close as practicable to the fracture. Furthermore, the distance between the plate and the bone ought to be kept small and long plates should be used to provide sufficient axial stiffness.

Biomechanical testing of the LCP--how can stability in locked internal fixators be controlled?

The gradual phasing-out of asbestos in automotive brake friction materials in many parts of the world has sparked the onset of extensive research and development into safer alternatives. As a result, the brake friction industry has seen the birth of different brake pads and shoes in the past decade, each with their own unique composition, yet performing the very same task and claiming to be better than others. This suggests that the selection of brake friction materials is based more on tradition and experimental trial and error rather than fundamental understanding. This review strives to eliminate the cloud of uncertainty by providing an insight into the pros and cons of the common ingredients and make-up used in contemporary dry and wet friction pads and shoes. In this paper typical brake materials are reviewed and their advantages and disadvantages in contemporary brake applications are discussed.

Review of automotive brake friction materials

Open wedge high tibial osteotomy: biomechanical investigation of the modified Arthrex Osteotomy Plate (Puddu Plate) and the TomoFix Plate.

List of Contributors. Series Editors' Foreword. Preface. 1. The Challenge of Wear (I. Hutchings). 1.1 Introduction. 1.2 Definitions and Development of Wear Studies. 1.3 Scope and Challenges. 1.4 Conclusions. 2. Classification of Wear Mechanisms/Models (K. Kato). 2.1 Introduction. 2.2 Classification of Wear Mechanisms and Wear Modes. 2.3 General Discussion of Wear Mechanisms and Their Models. 2.4 Conclusion. 3. Wear of metals: a Materials Response (S.K. Biswas). 3.1 Introduction. 3.2 Mild Wear and Transition to Severe Wear. 3.3 Strain Rate Estimates and Bulk Surface Temperature. 3.4 Summary. 4. Boundary Lubricated Wear (S. Hsu, R. Munro, M.C. Shen and R. S. Gates). 4.1 Introduction. 4.2 Lubricated Wear Classification. 4.3 Lubricated Wear Versus "Dry" Wear. 4.4 Wear Measurement in Well-Lubricated Systems. 4.5 Measurement Procedures. 4.6 Wear Mechanisms Under Lubricated Conditions. 4.7 Modeling of Lubricated Wear. 4.8 Summary. 5. Wear and Chemistry of Lubricants (A. Neville). 5.1 Encountering Wear in Tribological Contacts. 5.2 Lubricant Formulations - Drivers for Change. 5.3 Tribochemistry and Wear. 5.4 Antiwear Additive Technologies. 5.5 Extreme Pressure Additives. 5.6 Lubricating Non-Fe Materials. 6. Surface Chemistry in Tribology (A.J. Gelman and N. D. Spencer). 6.1 Introduction. 6.2 Boundary Lubrication and Oiliness Additives. 6.3 Zinc Dialkyldithiophosphate. 6.4 Hard Disk Lubrication. 6.5 Vapor-Phase Lubrication. 6.6 Tribology of Quasicrystals. 6.7 Conclusions. 7. Tribology of Engineered Surfaces (K. Holmberg & A. Matthews). 7.1 Introduction. 7.2 Definition of an Engineered Surface. 7.3 Tribomechanisms of Coated Surfaces. 7.4 Contact Types. 7.5 Advanced Coating Types. 7.6 Applications. 7.7 Conclusions. 8. Wear of Ceramics: Transitions and Tribochemical Reactions in Ceramics (S. Jahanmir). 8.1 Introduction. 8.2 Structure and Properties of Ceramics. 8.3 Wear Transitions. 8.4 Damage Formation in Hertzian Contacts. 8.5 Transition Loads in Sliding Contacts. 8.6 Ceramics in Tribological Applications. 9. Tribology of Diamond and Diamond-Like Carbon Films: An Overview (A. Erdemir). 9.1 General Overview. 9.2 Diamond Films. 9.3 Diamond-like Carbon Films. 9.4 Summary and Future Direction. 10. Tribology of Polymeric Solids and Their Composites (B. Briscoe and S.K. Sinha). 10.1 Introduction. 10.2 The Mechanisms of Polymer Friction. 10.3 Wear. 10.4 Tribology of Polymer Composites. 10.5 Environmental and Lubrication Effects. 10.6 A Case Study: Polymers in Hip and Knee Prosthetic Applications - Ultrahigh-Molecular-Weight Poly(ethylene) (UHMWPE). 10.7 Concluding Remarks. 11. Wear of polymer composites (K. Friedrich, Z. Zhang and P. Klein). 11.1 Introduction. 11.2 Sliding Wear of Filler Reinforced Polymer Composites. 11.3 Artificial Neural Networks Approach for Wear Prediction. 11.4 Fibre Orientation, Wear Mechanisms and Stress Conditions in Continuous Fibre Reinforced Composites. 11.5 Conclusions. 12. Third Body Reality - Consequences and Use of the Third Body Concept to Solve a Friction and Wear Problems (Y. Berthier). 12.1 Introduction. 12.2 Relationship Between the Third Body and Friction. 12.3 Relationship Between the Third Body and Wear. 12.4 What Methods Exist for Studying Friction and Wear? 12.5 The Third-Body Concept. 12.6 Functions and Behaviour of the Third Body. 12.7 Roles of the Materials in a Tribological Contact. 12.8 Taking into Account the Effects of the Mechanism. 12.9 Taking into Account the Effect of the First Bodies. 12.10 "Solid" Natural Third-Body Modelling. 12.11 Correspondence of the Strategy Proposed to Reality. 12.12 Control of Input Conditions. 12.13 Performing Experiments. 12.14 Conclusions. 13. Basic Principles of Fretting (P. Kapsa, S. Fouvry and L. Vincent). 13.1 Introduction. 13.2 Wear. 13.3 Industrial Needs. 13.4 Fretting in Assemblies. 13.5 Fretting Processes. 13.6 Fretting Parameters. 13.7 Conclusions. 14. Characterization and classification of abrasive particles and surfaces (G.W. Stachowiak, G.B. Stachowiak, D.V. de Pellegrin and P. Podsiadlo). 14.1 Introduction. 14.2 General Descriptors of Particle Shape. 14.3 Particle Angularity Parameters. 14.4 Particle Size Effect in Abrasive Wear. 14.5 Sharpness of Surfaces. 14.6 Classification of Abrasive Surfaces. 14.7 Summary. 15. Wear Mapping of materials (S. Hsu and M.C. Shen). 15.1 Introduction. 15.2 Basic Definition of Wear. 15.3 Wear as a System Function. 15.4 Wear Maps as a Classification Tool to Define the System. 15.5 Wear as an "Intrinsic" Material Property as Defined by Wear Maps. 15.6 Different Kinds of Wear Maps. 15.7 Application of Wear Maps. 15.8 Construction Techniques of Wear Maps. 15.9 Application Map Concept and Examples. 15.10 Future Wear Map Research. 16. Machine Failure and Its Avoidance - Tribology's Contribution to Effective Maintenance of Critical Machinery (B. Roylance). 16.1 Introduction. 16.2 Maintenance Practice and Tribological Principles. 16.3 Failure Diagnoses. 16.4 Condition-Based Maintenance. 16.5 Wear and Wear Debris Analysis. 16.6 Predicting the Remaining Useful Life and Evaluating the Cost Benefits. 16.7 Closure. Index.

Gwidon Stachowiak

Papers

Vegetable oil-based lubricants—A review of oxidation

Biomechanical testing of the LCP--how can stability in locked internal fixators be controlled?

Review of automotive brake friction materials

Open wedge high tibial osteotomy: biomechanical investigation of the modified Arthrex Osteotomy Plate (Puddu Plate) and the TomoFix Plate.

Wear - Materials, Mechanisms and Practice