Newsletter Mission Statement
Keeping pace with the development of new technologies has always been one of VAC AERO’s main concerns. Given our role as a leader in vacuum heat treating and special processing, the aim of our Newsletter is (1) to facilitate discussion among our customers, technical and educational communities and suppliers on a variety of metallurgical issues, processes, technologies and equipment (2) to promote, collaborate and help others in their search for solutions on important issues in the practice and application of heat treating, metallurgy & surface engineering, (3) to enhance ongoing innovation capability of vacuum furnace engineering and component design and (4) to recognize early achievement in our field by encouraging promising younger individuals working in educational research.
Links to Newsletter Archives Since 2007
Metal Expansion Rates – How to meaningfully use them in brazing – by Dan Kay
Braze Welding (BW) — A New Expanded Definition is Needed – by Dan Kay
An Old High-Temp Differential-Expansion Problem – by Dan Kay
Feed BFM From One Side, Inspect On Other Side – by Dan Kay
Shell & Tube Heat Exchangers — Methods to Seal Tube-to-Header Joints – by Dan Kay
Vacuum Gauges – by VAC AERO International
What Causes “Spatter” of BFM in Furnace Brazing? – by Dan Kay
Vacuum Valves – Types and Operation – by VAC AERO International
The Nadcap Accreditation Process – by VAC AERO International
Can Cadmium and Zinc Be Used in Brazing – by Dan Kay
Brazing-Drawing Challenge – Part 2 (Answers) – by Dan Kay
The Importance of Vacuum Furnace Maintenance – by Dan Herring
Brazing-Drawing Challenge – by Dan Kay
Vertical Oil Quench Vacuum Furnace Overview – by VAC AERO International
Temperature Uniformity Survey (TUS) Fixturing – by Dan Kay
Overview of a Vertical Gas Quenching Vacuum Furnace – by VAC AERO International
“Dummy-blocks” used in Brazing Furnaces – by Dan Kay
Seven (7) Very Important Tips for Improving Vacuum Performance and Operation – by VAC AERO International
Controlled “Heat-down” For Vacuum Brazing – by Dan Kay
Magnesium (Mg) Vapor in Vacuum-Furnaces Used for Brazing Aluminum Components – by Dan Kay
Vacuum Furnace Safety – by VAC AERO International
Don’t Vacuum-Braze Metals Containing Zinc – by Dan Kay
Batch and Continuous Furnaces – by VAC AERO International
Can Brazing Stop-Off Usage be Abused? – by Dan Kay
Update on Vacuum Furnace Gauges – by VAC AERO International
Are Recessed Braze-Fillets Okay? – by Dan Kay
Instrumentation and Process Control in Vacuum Furnaces – by VAC AERO International
Revisiting Refrigeration of Brazing Paste. Is Refrigeration Really Necessary? – by Dan Kay
Process Applications Run in Vacuum Furnaces – by VAC AERO International
Vacuum Brazing of EGR Coolers – by Dan Kay
Vacuum Systems for Composite Manufacturing – by VAC AERO International
Definitions: Vacuum Terms, Related Terminology – by Alan Charky, VAC AERO International
Don’t ever use a Brazing Paste-flux when Vacuum Brazing! – by Dan Kay
Torricelli’s Importance in Vacuum Brazing History – by Dan Kay
Maintenance of Vacuum Furnaces – by VAC AERO International
Vacuum Vapor Degreasing – by VAC AERO International
Vacuum Furnace Heat Exchangers: Design, Function & Factors Affecting Performance – by VAC AERO International
Degreasing (oil removal) before Oxide Removal (Pickling, etc.) – by Dan Kay
An Aluminum Brazing Problem – by Dan Kay
Vacuum Furnace Heating Elements – by VAC AERO International
Be sure to “Blister Test” your nickel-plating before brazing – By Dan Kay
Carbon-fiber reinforced carbon (C/C) fixturing for brazing? – by Dan Kay
Use of Graphite Composites in Hardening and Sintering Technology – by VAC AERO International
Vacuum Furnace Hot Zones: Metal and Carbon Configurations – by VAC AERO International
One More Frequently Misused Brazing Term: “Brittle” – by Dan Kay
Two Frequently Misused Brazing Terms: Passivation, and Defect – by Dan Kay
Cold Wall Vacuum Furnaces – by VAC AERO International
“Brazing Definition” – Clarification of the Terminology – by Dan Kay
Essential Criteria for Brazing: Item 3a – Proper joint fit-up – by Dan Kay
A Brief Discussion of Pressure and Vacuum Levels – by VAC AERO International
Essential Criteria for Brazing: Item 3b – Proper joint fit-up and Surface Roughness concerns – by Dan Kay
Essential Criteria for Brazing: Item 4 – Proper Choice of Brazing Filler Metal (BFM) – by Dan Kay
Kay & Associates: Brazing Quiz – by Dan Kay
Essential Criteria for Brazing: Item 4a – Brazing filler metal powder used in making brazing-paste – by Dan Kay
Space Simulation Chambers – Part 1 – by VAC AERO International
Answers to the Kay & Associates Brazing Quiz – by Dan Kay
Preventive Maintenance Extends Hot-Zone Life – by VAC AERO International
Getter Materials – by VAC AERO International
Space Simulation Chambers – Part 2 – by VAC AERO International
Essential Criteria for Brazing: Item 4c – Brazing filler metal (BFM) – How much should be used? – by Dan Kay
Finding and Fixing Vacuum Leaks – by VAC AERO International
Vacuum Technology at CERN – by VAC AERO International
Essential Criteria for Brazing: Item 5 – Fixturing: Keeping weight to a minimum (Part A) – by Dan Kay
Considerations in Vacuum Vessel Design – by VAC AERO International
Vacuum Technology at CERN – Part 2 – by VAC AERO International
Essential Criteria for Brazing: Item 5 – Fixturing: Keeping weight to a minimum (Part B) – by Dan Kay
Cold Traps – by VAC AERO International
Vacuum Technology at CERN – Part 3 – by VAC AERO International
Vacuum Degassing of Steel – by VAC AERO International
Hot Wall Vacuum Retort Furnaces – by VAC AERO International
Essential Criteria for Brazing: Item 7 – Knowledgeable Inspection of Finished Brazed Assemblies – by Dan Kay
Torch-Braze Repair of Vacuum Brazed Components – by Dan Kay
Identifying the Cause of Tool and Die Failure – by George Vander Voort
An Introduction to Vacuum Pumps – by VAC AERO International
Metallurgy for the Vacuum Heat Treater – by VAC AERO International
Stress Concentration – by Dan Kay
Conducting the Failure Examination – by George Vander Voort
Oil Sealed Rotary Vane Pumps – by VAC AERO International
Overview of Common Vacuum Furnace Equipment – by VAC AERO International
Brazing Paste Dispensing Tips – by Dan Kay
Metallography and Microstructure of Aluminum and Alloys – by George Vander Voort
Vacuum Science and Engineering – By VAC AERO International
Essential Criteria for Brazing: Item 2 – Proper cleaning—role of tumble deburring in surface-prep (Part D) – By Dan Kay
Dry Pumps: Claw Pumps – By VAC AERO International
Brazing Paste: What happens when the BFM-paste “separates”? – By Dan Kay
Dry Pumps: Screw Type – By VAC AERO International
Essential Criteria for Brazing: Item 2 – Proper cleaning—role of grit blasting in surface-prep (Part C) – By Dan Kay
Vacuum Pump Maintenance – by VAC AERO International
Discolored Work in a Vacuum Furnace – The Heat Treat Community Answers the Clarion Call – By Dan Herring
Electroless Nickel Plating as a Brazing Filler Metal – By Dan Kay
Vacuum Pump Oil: The “Circulatory System” of the Vacuum Furnace – By VAC AERO International
Essential Criteria for Brazing: Item 2 — Proper Cleaning/handling means wearing gloves (Part B) – By Dan Kay
The Fundamentals of Vacuum Theory – by VAC AERO International
Essential Criteria for Brazing: Item 1 — Proper Cleaning – By Dan Kay
Roots Blowers (aka Booster Pumps) – by VAC AERO International
Essential Criteria for Brazing: Item 1 — Proper Design for Brazing – By Dan Kay
Microstructure of Nitrided Steels – By George Vander Voort
Brazing Filler Metal (BFM) “Certification of Conformance” – Have you ever had a problem with one? – by Dan Kay
Safety in the Metallography Laboratory – by George Vander Voort
Oil for Vacuum Pumps – by Howard Tring
Tips for Selecting Vacuum Furnace Equipment – by VAC AERO International
Braze Fixturing via Tack-welding — the Good and the Bad! – by Dan Kay
Use of the Scanning Electron Microscope in Failure Analysis – by George Vander Voort
Calculating Evacuation Time – by Howard Tring
Gas-quenching when vacuum-brazing – any dangers? – by Dan Kay
Metallographic Imaging Modes – by George Vander Voort
Maintaining Oil Diffusion Pumps – by Howard Tring
The Interlamellar Spacing of Pearlite – by George Vander Voort
Gas Ballasting of Mechanical Oil Sealed Rotary Vacuum Pumps – by Howard Tring
Dry Lubricants for Vacuum Service – by VAC AERO International
Braze Inspection – Look for Concave Fillets – by Dan Kay
Deformation and Annealing of Cartridge Brass – by George Vander Voort
The Use of Molybdenum in Vacuum Furnace Applications – by VAC AERO International
Removing Magnesium Buildup in Aluminum-brazing Vacuum Furnaces – by Dan Kay
Metallographic Procedures for Cast Irons – by George Vander Voort
The Use of Tungsten in Vacuum Furnace Applications – by VAC AERO International
Concerns re Furnace Brazing of Carbon and Alloy Steels When Using Copper Brazing Filler Metal – by Dan Kay
Measurement of the Volume Fraction of Beta Phase in Naval Brass – by George Vander Voort
Vacuum Deposition Processes – by Dan Herring
Is it okay to cross-section brazed joints for accept/reject? – by Dan Kay
Using the Control Chart Approach to Evaluate Hardness Tester Performance – by George Vander Voort
Evaporation – by Dan Herring
321 Stainless Steel — Is it a Good Choice for Brazing? – by Dan Kay
Very Low Loads in Micro-indentation Tests Must Be Avoided – by George Vander Voort
What is the Purpose of a Vacuum Pump – by VAC AERO International
Pressure Relief Valves – by VAC AERO International
Induction Brazing vs. Vacuum Brazing – by Dan Kay
Avoid Microindentation Hardness Testing at Low Loads! – by George Vander Voort
Conductance in Vacuum Pumping Systems – by VAC AERO International
Vacuum Diffusion Bonding -by Design – by Dan Herring
303 stainless steel — Is it a good choice for brazing? – by Dan Kay
What is a Normal, Uni-Modal Grain Size Distribution? – by George Vander Voort
Proper Selection and Use of Vacuum Gauges – by VAC AERO International
Cleanup of Contaminated Vacuum Furnaces – by VAC AERO International
Brazing Furnaces: Vacuum vs. Continuous-Belt – by Dan Kay
Metallographic Examination of Medical Implants – by George Vander Voort
The Role of Lubricants in Vacuum Furnace Seals – by VAC AERO International
Erosion of Base-Metals by Brazing Filler Metals – by Dan Kay
Metallographic Examination of Bronze Bracelets from Hasanlu – by George Vander Voort
Simple Physics for the High Vacuum Processing Industry – by Howard Tring
Loading of Parts in Vacuum Furnace – by VAC AERO International
Using Titanium “Getters” in Vacuum Brazing – by Dan Kay
Propeller Shaft of the USS Monitor – by George Vander Voort
When to Use a Partial Pressure in a Vacuum Furnace – by Jeff Pritchard
Five Main Reasons for using Vacuum – by Howard Tring
Mg-gettering in Vacuum Brazing of Aluminum – by Dan Kay
Influence of the Equations Defining HV and HK on Precision – by George Vander Voort
The Oil Sealed Rotary Vane Vacuum Pumps – Background and Designs – by Howard Tring
Residual Gas Analyzers – by VAC AERO International
Dewpoint Control in Vacuum-Furnace Brazing – by Dan Kay
Fracture of a 17th Century Japanese Helmet – by George Vander Voort
A Vacuum Heat Treater’s Library – by Dan Herring
Piping Atmosphere-gas to a Brazing Furnace – by Dan Kay
Determining the Nodularity of Graphite in Ductile Iron Using ASTM E2567 – by George Vander Voort
Case Study: The Benefits of High-Pressure Gas Quenching in Dimensional Control – by Dan Herring
Surface-Roughness of Parts to be Vacuum Brazed – by Dan Kay
Martensite and the Control of Retained Austenite – by George Vander Voort
The Rotary Vane (RV) Vacuum Pump Turns 25 – by Howard Tring
A Layman’s Guide to Understanding The Theory of Gases – by Dan Herring
Braze Joint Design: How Much Overlap is Enough? – by Dan Kay
Metallographic Preparation of Titanium and Its Alloys – by George Vander Voort
Braze Joint Design: “Percentage of Voids in a Joint can Increase with Overlap Distance” – by Dan Kay
Oil Diffusion Pump Controls – by Howard Tring
Vapor Pressure and Evaporation in Vacuum Furnaces – by VAC AERO International
Braze-Fixturing Tubing/piping Using Prick-punching – by Dan Kay
Revealing Prior-Austenite Grain Boundaries – by George Vander Voort
800°F, 840°F, 450°C — Which temperature defines brazing? – by Dan Kay
Difficulties Using Standard Chart Methods for Rating Non-Metallic Inclusions – by George Vander Voort
Inlet Filters for Mechanical Vacuum Pumps – by Howard Tring
Vacuum Brazing: “Braze with the Weakest Vacuum You Can Get Away With” – by Dan Kay
Heat Treatment of Landing Gear – by D. Scott MacKenzie
Delineation and Measurement of Grain Size by EBSD – by George Vander Voort
Looking after Mechanical Vacuum Pumps – by Howard Tring
Why is a nitrogen atmosphere disallowed when nickel-brazing per AMS 2675? – by Dan Kay
Selective Etching and Quantitative Measurements Used to Assess the Thermal Exposure to the Lower Head of the Three-Mile Island Unit 2 Nuclear Reactor – by George Vander Voort
Abradable Coatings used for Gas Path Seals in Turbine Engines – by VAC AERO International
New Considerations when Buying a Vacuum Furnace – by Alan Charky, VAC AERO International
Saving Money by Maximizing Furnace Uptime Productivity by VAC AERO International
Brazing Filler Metal Powder Mesh Size by Dan Kay
Grain Size Measurement: The Saltykov Rectangle by George Vander Voort
The Oil Sealed Rotary Vacuum Pump by Howard Tring
Backstreaming – by VAC AERO International
Isothermal Solidification – by Dan Kay
Measuring the Grain Size of Specimens with Deformed Grains – by George Vander Voort
Understanding Vacuum Measurement Units – by Howard Tring
The Famous Joint-Strength vs. Joint-Clearance Chart – by Dan Kay
Grain Size Measurements by the Triple Point Count Method – by George Vander Voort
Vacuum Gauges Used on Vacuum Furnaces – by Howard Tring
Selecting the Right Vacuum Furnace for the Job – by VAC AERO International
Stainless QC-coupons to Determine Atmosphere-Quality In Your Furnace – by Dan Kay
Metallography of Iron-Nickel Meteorites – Part 1: Background – by George Vander Voort
Dimensional Changes After Heat Treatment – by Dan Herring
304 vs. 304L – An Answer to Carbide-Precipitation Issues – by Dan Kay
Mechanical Booster Pumps for Vacuum Systems – by Howard Tring
Low-Temperature Vacuum Processing – by VAC AERO International
Two Frequently Misused Brazing Terms: “Passivation” (vs. pickling), and “Defect” – by Dan Kay
Measuring Inclusion Content by ASTM E 1245 – by George Vander Voort
Types of Backfill, Partial Pressure and Cooling Gases for Vacuum Heat Treatment – by VAC AERO International
Stainless Steel Brazing on Graphite Fixtures? – by Dan Kay
Methanol Pipeline Failure in the Canyon Express Pipeline System – by George Vander Voort
Summer Maintenance of Vacuum Systems – by Howard Tring
Are Your Hands Clean Enough to Handle Parts for Brazing? – by Dan Kay
Metallography of Iron-Nickel Meteorites – Part 2: Microstructure – by George Vander Voort
Shaft Seals for Rotating Shafts – by Howard Tring
Intergranular Oxidation (IGO) / Intergranular Attack (IGA) – by VAC AERO International
Gas Molecules and Gas Flow – by Howard Tring
A Curious Case of Part Contamination in a Vacuum Furnace – by Dan Herring
Brazing vs. Soldering – by Dan Kay
Decarburization – by George Vander Voort
Conductance and Throughput in Vacuum Pipelines – by Howard Tring
A Brief History of Vacuum Technology – by Dan Herring
Liquid Penetrant Inspection in Brazing? – by Dan Kay
Metallography of Iron-Nickel Meteorites – Part 3: Microstructure in Color – by George Vander Voort
Pressure and Throughput Distribution in Vacuum Systems – by Howard Tring
Vacuum Heat Treatment of Fasteners – by VAC AERO International
X-Ray Inspection of Brazed Joints – by Dan Kay
Obtaining Consistent Vickers Hardness at Loads ≤ 100 Grams Force – by George Vander Voort
Important Considerations for Establishing a New Vacuum Heat Treating Capability – by Alan Charky, VAC AERO International
Use of Active Brazing Alloys (ABA) in Vacuum Furnaces – by Dan Kay
Introduction to Stereological Principles – by George Vander Voort
Pumps for High and Ultra-High Vacuum – by VAC AERO International
Centerline Eutectics in Ni-brazing – by Dan Kay
Metallographic Preparation of Tool Steels – by George Vander Voort
Tool Steel Carbides – by Dan Herring
Argon Can Be Lethal! – by Dan Kay
Revealing the Microstructure of Tool Steels – by George Vander Voort
Using Vacuum Furnaces to Achieve Lean, Green and Agile Manufacturing – by VAC AERO International
Boxing of Components – by Dan Kay
Metallography and Microstructure of Aluminum and Alloys – by George Vander Voort
Refrigeration of Brazing Paste? – by Dan Kay
Bias in Grain Size Chart Ratings – by George Vander Voort
Tips For Improving Vacuum Performance & Operation – by VAC AERO International
Can a Brazing-Flux be used in Vacuum Brazing? – by Dan Kay
Dimension Braze-Fillets on Drawings? – by Dan Kay
The Value of Color Metallographic Techniques in the Study of Welds – by George Vander Voort
Vacuum Furnace Leak-up Rates for Successful Brazing – by Dan Kay
Metallographic Procedures for Precious Metals – by George Vander Voort
Helium leak detection in vacuum brazing – by Dan Kay
Measurement of Grain Shape Uniformity – by George Vander Voort
Effect of Virtual Leaks in Vacuum Furnace Brazing – by Dan Kay
Measurement of Grain Size in Twinned FCC Alloys – by George Vander Voort
Eutectics – the good and the bad! – by Dan Kay
Grain Size Measurement: The Jeffries Planimetric Method – by George Vander Voort
Eliminating “holds” in Heating Rates During Vacuum-Brazing Cycles – by Dan Kay
Grain Size Measurement: The Heyn Intercept Method – by George Vander Voort
Controlling Suppliers and Customers: Key to Successful In-House Brazing? – by Dan Kay
Vertical Test Specimen for Furnace Brazing – by Dan Kay
Metallography of Superalloys – by George Vander Voort
Microstructure of Ferrous Alloys – by George Vander Voort
Brazing Base Metals Containing Small Amounts of Titanium, Aluminum – by Dan Kay
Metallography of Surface Treatments and Coatings – by George Vander Voort
Shelf-Life and Expiration-Dates for Brazing Paste – by Dan Kay
Color Metallography – by George Vander Voort
Making Your Own Brazing Paste – by Dan Kay
A Layman’s View of Plasma Spray Coating Metallography – by George Vander Voort
Using a “Stop-Off” in Brazing – by Dan Kay
Identification of Phases in Stainless Steels by Etching – by George Vander Voort
Can I Use Standard Aerospace Vacuum Furnaces to Braze Aluminum? – by Dan Kay
Picric Acid – Hazards and Safe Usage – by George Vander Voort
Effect of Heating Rates on Distortion, Fracture of Assemblies Being Brazed – by Dan Kay
Microstructure of Isothermally-Treated Steels – by George Vander Voort
Can Your Suppliers Hurt Your In-house Brazing? – by Dan Kay
Metallographic Specimen Preparation for Electron Backscattered Diffraction – by George Vander Voort
Study of Selective Etching of Carbides in Steel – by George Vander Voort
Landing-Gear Heat Treatment – by Dan Herring
Wide Gap Brazing when Parts don’t Fit Together well for Brazing – by Dan Kay
Introduction to Quantitative Metallography – by George Vander Voort
Hot Zone Selection for Vacuum Brazing of Superalloys – by Jeff Pritchard, Vac Aero International Inc.
Voids in Brazed Joints – by Dan Kay
Differential Metal Expansion & Brazing Challenge Question – by Dan Kay
Thermocouples in Furnace Brazing – by Dan Kay
Fillets in Brazing – by Dan Kay
Repair Brazing – Fixing faulty jobs and worn-out components – by Dan Kay
Liquation of Brazing Filler Metals – Good or Bad? – by Dan Kay
Honeycomb-Brazing Essentials for Successful Use As Turbine Seals – by Dan Kay
Reducing Metal-Oxides in Brazing – by Dan Kay
Coating Gas Turbine Engine Blades Using HVOF – by Jeff Pritchard, Vac Aero International Inc.
Welding of High Strength Steel Landing Gear Components – by Jeff Pritchard, Vac Aero International Inc.
Brazing – A Great joining Process for this 21st Century! – by Dan Kay
Brazing in a Vacuum “Atmosphere” – by Dan Kay
Partial Pressure Brazing – by Dan Kay
Selecting Brazing Fixture Materials – by Dan Kay
Are the use of dead-weights for fixturing a recommended practice? – by Dan Kay
How to Determine Braze Gap-Clearances for Your Furnace – by Dan Kay
Braze Joint Design Considerations – by Dan Kay
Buying a Vacuum Furnace: New versus Used – by Jeff Pritchard, Vac Aero International Inc.
Why Heat Treat in a Vacuum? – by Jeff Pritchard, VAC AERO International Inc.
Eutectic Melting – by Jeff Pritchard, VAC AERO International Inc.
Using Thermal Spray for Repair of Service-Damaged Parts
Vacuum Furnace Quenching Systems: External versus Internal – by Jeff Pritchard, VAC AERO International Inc.
Cleaning Practices Prior to Vacuum Heat Treating – by Jeff Pritchard, VAC AERO International Inc.
Loading Practices for Vacuum Processing – by Jeff Pritchard, VAC AERO International Inc.
Fixture Design for Vacuum Processing – by Jeff Pritchard, VAC AERO International Inc.
Temperature Uniformity Surveys – by Jeff Pritchard, VAC AERO International Inc.
Temperature Measurement in Vacuum Furnaces – by Jeff Pritchard, VAC AERO International Inc.
Maintenance Procedures for Vacuum Furnaces – by Jeff Pritchard, VAC AERO International Inc.
Vacuum Brazing Techniques – by Jeff Pritchard, VAC AERO International Inc.
Hot Zone Repair, Re-build and Retrofit – by Jeff Pritchard, VAC AERO International Inc.
VAC AERO Launches “What’s Hot!” Newsletter
VAC AERO Develops New Hybrid Vacuum Furnace Control System
Advanced Techniques For Distortion Control During Vacuum Oil Quenching – by Jeff Pritchard, VAC AERO International Inc.
Vacuum Hardening High-Strength Steels: Oil Versus Gas Quenching – by Jeff Pritchard, VAC AERO International Inc.
Hot Zone Design for Vacuum Furnaces – by Jeff Pritchard, VAC AERO International Inc.
VAC AERO is a World Leader in the Processing of Landing Gear Components
SiC-Reinforced Aluminum Alloy Coatings Produced by Cold Spray Process
VAC AERO Operates three of the Largest Oil Quench Furnace
Manufacturers of Premier Vacuum Heat Treating Furnaces & Specialty Coating Services.
VAC AERO designs and builds vacuum furnace systems and controls with the highest quality standards for any of your specialized processing needs. From small horizontal units to large vertical models VAC AERO vacuum heat treating furnaces are ideal for a broad range of vacuum heat treatment applications of engineered materials, and specialty alloys. VAC AERO vacuum furnaces operate worldwide in diverse applications in aerospace, power generation, and other high-tech industries. VAC AERO also offers vacuum heat treating and specialty coating services to the aerospace and high-tech industries including; plasma and high-velocity Oxy-fuel (HVOF) spray coatings as well as inorganic paint and pack coatings. In business since 1959 VAC AERO operates four plants in Ontario and Quebec, Canada.