Room Temperature Solid-Phase Bonding via Microasperity Surface Engineering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing room temperature bonding methods require high-cost facilities, complex pretreatment processes, and often need to be performed in ultrahigh vacuum or involve expensive thin film formation, making them difficult to industrially utilize.
Innovation Solution
A jointed body with a specific microasperity-shaped joining surface that allows solid-phase joining at normal temperatures in air, using a manufacturing method where the joining surfaces have a surface roughness of 0.2 micrometers or less and an increased actual surface area, enabling spontaneous joining with low pressure and small vibration, thus avoiding the need for expensive pretreatments and high-temperature processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional room temperature bonding methods are used, then bonding can be achieved at normal temperature, but expensive pretreatment processes and high-cost facilities are required
Solution Approach 1:
The invention changes the surface topography parameter by creating micro-asperities with specific height distributions (peak height h1, intermediate height h2, valley depth d1) on the bonding surfaces. This parameter change enables room temperature bonding without expensive pretreatment by controlling how surface atoms contact and bond, transforming the bonding mechanism from requiring ultra-c clean surfaces to utilizing controlled micro-roughness for atomic-level contact.
2Object-generated harmful factors
If friction welding or ultrasonic bonding is used, then films on bonding surfaces can be removed, but heat strain and structural change occur in the vicinity of the junction interface
Solution Approach 1:
The invention performs preliminary action by pre-forming micro-asperities on the bonding surfaces before the actual bonding process. These micro-asperities are created through controlled surface treatment that prepares the surfaces for bonding without requiring high-temperature heating during the bonding itself. The micro-asperity structure ensures that when bonding occurs at room temperature, films are effectively managed while minimizing heat strain and preserving the structural stability of the materials near the junction interface.
3Strength
If bonding surfaces are subjected to ultrasonic vibration with high pressure, then bonding can be achieved, but the shape and features of jointed members are restricted
Solution Approach 1:
The invention changes the bonding mechanism by utilizing micro-asperity contact instead of requiring ultrasonic vibration and high pressure. The specific micro-asperity parameters (peak height h1 of 0.5-2.0 μm, intermediate height h2 of 0.2-1.0 μm, valley depth d1 of 0.3-1.5 μm) enable bonding at room temperature with minimal pressure and without ultrasonic vibration, thereby maintaining the shape flexibility and versatility of jointed members while achieving strong bonding.
4Object-generated harmful factors
If inert gas beam or plasma is used for pretreatment, then films can be removed from bonding surfaces, but high-cost facilities and ultrahigh vacuum conditions are required
Solution Approach 1:
The invention replaces expensive, complex facilities (inert gas beam equipment, plasma generators, ultrahigh vacuum systems) with a simpler, more economical approach: pre-forming micro-asperities on surfaces through relatively simple surface treatment processes. This disposable-like approach to surface preparation eliminates the need for costly ongoing pretreatment facilities and ultrahigh vacuum conditions, making the bonding process industrially viable while still achieving effective film removal and strong bonding.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables strong, efficient solid-phase joining of metal members at normal temperatures in air, maintaining the intrinsic properties of the joined materials with minimal structural change, and eliminating the need for expensive facilities and processes.
Implementation Method 1
room temperature bonding is that which utilizes atomic force (surface energy) possessed intrinsically by surface atoms of members to be bonded
Implementation Method 2
mechanical friction removes films such as oxidation films on the bonding surfaces to result in room temperature bonding with assistance by the activation of the surface atoms due to friction heat
Implementation Method 3
mechanical friction removes films such as oxidation films on the bonding surfaces
Implementation Method 4
mechanical friction removes films such as oxidation films on the bonding surfaces to result in room temperature bonding
Implementation Method 5
attractive force (atomic force) acting between their surface atoms exceeds an internal stress that acts in the opposite direction
Implementation Method 6
strong bonding can be allowed even by a small input energy, so that large heat strain and structural change will be prevented from occurring in the vicinity of the junction interface
Data Source
AI summary
A jointed body that has been solid-phase jointed at normal temperature and that has a non-conventional structure is presented. The jointed body is formed by solid-phase joining a first jointed member to a second jointed member, and has a junction interface between the first member and the second member. This jointed body includes an average crystal grain size in a near interface structure that constitutes a near interface area having a total width of 20 micrometers and extending at both sides of the junction interface as a center is 75-100% of an average crystal grain size in an around interface structure that constitutes around interface areas located at both outer sides of the near interface area. In the jointed body, the near interface structure after the joining is almost the same as the structure before the joining, allowing the jointed body to exert similar characteristics to the jointed members.