Engineering Design for Wear, Second Edition, Revised and Expanded

by Bayer; Raymond G.

• ISBN13: 9780824747725
• ISBN10: 0824747720
• Edition: 2nd
• Format: Hardcover
• Copyright: 2004-06-25
• Publisher: CRC Press

Summary

A modern presentation of approaches to wear design, this significantly revised and expanded Second Edition offers methods suited for meeting specific wear performance requirements; numerous design studies highlighting strategies for use with different tribological elements and mechanical systems; proven tactics for resolving wear-related problems; and a plethora of real-world case studies. Engineering Design for Wear explores the complex wear behavior of materials as it concerns design and depicts contemporary engineering models used for predicting wear. Revised and expanded, this new edition offers numerous additions and enhancements including a new chapter on design triage, and much more.

Author Biography

Raymond G. Bayer is a Consultant based in Vestal, New York

Table of Contents

Preface	v
Design Perspective of Wear Behavior	1	(44)
Introduction	1	(1)
System Nature of Wear	2	(1)
Basic Mechanisms of Wear	3	(2)
Mild and Severe Wear Behavior	5	(1)
Operational Categories of Tribosystems	5	(1)
Two-Body Tribosystems	6	(11)
One-Body Tribosystems	17	(1)
Materials and Wear Behavior	17	(28)
Engineering Models for Wear	45	(92)
Introduction	45	(4)
Wear and Wear Rate Relationships for Sliding Wear	49	(6)
Wear and Wear Rate Relationships for Abrasive Wear	55	(1)
Zero Wear and Measurable Wear Models for Sliding	56	(19)
Percussive Impact Wear Models	75	(14)
Model for Rolling Wear	89	(7)
Model for Ball and Roller Bearing Wear	96	(8)
Models for Journal Bearing Wear	104	(19)
Models for Erosive Wear	123	(4)
Models for Tool Wear	127	(10)
Wear Design	137	(14)
General	137	(3)
System Analysis	140	(2)
Model Selection and Development	142	(5)
Database Identification and Development	147	(1)
Verification	147	(1)
Design Triage	148	(3)
Design Guidelines	151	(10)
Introduction	151	(1)
Guidelines	151	(10)
Reliance on Analytical Design Methods Increases the Degree of Conservatism Required	151	(1)
Wear is a System Property; Utilize All Design Parameters That Can Influence Wear	151	(1)
Approach Extrapolation of Data and Extension of Designs Cautiously	152	(1)
Design with Limits and Characteristics of Materials in Mind	152	(1)
Metals and Polymers Tend to Require Different Designs	152	(1)
Design So That a Mild Wear Condition Exists	153	(1)
A Minimum Requirement for Material Selection is That the Material Should be Stable in the Operating Environment	153	(1)
While Fluid or EHD Lubrication is very Effective for Reducing Wear, Specific Designs are Required to Insure this Form of Lubrication	153	(1)
Minimize Exposure to Abrasive Particles	154	(1)
In Abrasive Situations Make the Wear Surfaces Harder than the Abrasives	154	(1)
Optimize Contact Geometry to Minimize Stresses	154	(1)
Use a Lubricant Whenever Possible	155	(1)
Use Dissimilar Materials	155	(1)
Increasing Hardness Tends to Reduce Wear	155	(1)
To Increase System Life (Reduce System Wear), It is Sometimes Necessary to Increase the Hardness of Both Members	155	(1)
Rolling is Preferred Over Sliding	155	(1)
Sliding or Fretting Motions Should be Eliminated in Impact Wear Situations	156	(1)
Compound Impact Situations Can Often be Treated as a Sliding Wear Situation in Which the Loads (Stresses) are Determined by the Impact	156	(1)
Impacts Should be Avoided in Sliding and Rolling Contacts	156	(1)
Elastomers Frequently Outperform Harder Materials and Reduce Counterface Wear in Impact Situations	156	(1)
Thicknesses of Conventional Coatings Generally Should be Greater than 100 μm	156	(1)
Use Moderate Surface Roughnesses	157	(1)
Avoid the Use of Stainless Steel Shafting with Impregnated Sintered Bronze Bearings	157	(1)
When Molded Filled Plastics Tend to Exhibit Significantly Different Initial and Long-Term Wear Behavior	157	(1)
When Glass or Other Hard Fillers are Used, the Hardness of the Counterface Should be Equal to or Greater than that of the Filler	157	(1)
The Tendency for Galling to Occur can be Reduced by Using Dissimilar and Hard Materials of Low Ductility, Lubrication, and Rougher Surfaces	158	(1)
Avoid the Use of Designs in Which Fretting Motions Can Occur	158	(1)
When Fretting Motions are Present, Design to Optimize Sliding Wear Life and to Minimize Abrasive Wear	158	(1)
Sacrificial Wear Design Should be Considered an Option When Satisfactory Life Cannot be Achieved with Available Materials	158	(1)
Conform to Vendor Recommendations Regarding Optimum Wear Performance	159	(1)
Changes Associated with Design Modifications or New Applications Should be Reviewed Carefully with Respect to their Potential Effect on Wear Behavior	159	(1)
Provide Adequate Clearance in Journal Bearings	159	(1)
The Severity of the Wear (Wear Rate) in Rolling, Sliding, and Impact Wear Situations can Generally be Correlated to the Ratio of Operating Stress Over Yield Stress (Stress Ratio)	159	(1)
Design so that Severe Wear Mechanisms Associated with Adhesion and Single-Cycle Deformation do not Occur	160	(1)
Design Examples	161	(164)
Introduction	161	(1)
Printer Cartridge	161	(8)
Vacuum Probe	169	(4)
Forms Thickness Control	173	(4)
Plastic Gears	177	(2)
Type Carrier Backstop	179	(8)
Thermal Conduction Module	187	(15)
Hammer Pivot	202	(14)
Band-Platen Interface	216	(14)
Push Rod Tip	230	(7)
Band-Ribbon Interface	237	(18)
Magnetic Read Head	255	(14)
Erosion Applications	269	(14)
Abrasion Applications	283	(9)
Nuclear Valve	292	(8)
Plug Valve	300	(4)
Screwnut-Spindle	304	(3)
Cardan Joint	307	(6)
Electromagnetic Clutch	313	(12)
Problem Solving Methodology	325	(4)
General	325	(1)
Failure Analysis	326	(1)
Hypothesis Development	327	(1)
Testing	328	(1)
Problem Solving Case Studies	329	(38)
Introduction	329	(1)
Card Edge Connector Fretting	329	(7)
Excessive Carrier Backstop Wear	336	(3)
Push Rod Tip Failure	339	(6)
Separator Roll	345	(4)
Motor Brush Life	349	(4)
Memory Disk Drive Failures	353	(1)
Erosion in Fans and Blowers	354	(1)
Hydraulic Structure Wear	355	(3)
Teeter Bearing Wear	358	(9)
Glossary of Wear Mechanisms, Related Terms, and Phenomena	367	(8)
Appendix I: Values of m and n for Use with the Hertz Contact Stress Equations	375	(1)
Appendix II: Zero Wear Factors and Coefficients of Friction for Sliding	376	(8)
Appendix III: Wear and Friction Data	384	(11)
Appendix IV: Approximate Relationship Between Vickers Hardness and Yield Point in Shear	395	(1)
Appendix V: Galling Thershold Stress	396	(7)
Appendix VI: Wear Relationships for Sliding Wear Based on the Zero and Measurable Wear Models for Sliding	403	(7)
Appendix VII: Model for the Effect of Fluid Lubrication on Zero Wear Factors	410	(7)
Index	417