Brake Disc Wear Layer Using Duplex Steel and Hard Particles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Friction brakes for motor vehicles experience significant wear and corrosion due to the friction between the brake disc and pad, leading to abrasion and brake dust emission, which existing wear protection layers fail to adequately address.
Innovation Solution
A friction brake body with a wear protection layer made of ferritic-austenitic steel, characterized by a two-phase structure with austenite islands and finely distributed hard material particles, along with an intermediate layer of pure ferritic-austenitic steel, providing enhanced corrosion resistance, crack resistance, and wear resistance, applied using methods like laser deposition welding or thermal spraying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a wear protection layer is applied to reduce abrasion, then wear resistance is improved, but the layer may be prone to cracking and corrosion under thermomechanical stress
Solution Approach 1:
The wear protection layer is made of ferritic-austenitic steel, a composite material combining two phases with complementary properties: ferrite provides corrosion and crack resistance, while austenite provides ductility. This composite structure allows the layer to simultaneously achieve high wear resistance, crack resistance, and corrosion resistance without compromising reliability
Solution Approach 2:
The patent applies local quality by creating an intermediate layer of pure ferritic-austenitic steel between the wear protection layer and the base body. This intermediate layer has different properties than the wear protection layer itself, specifically providing enhanced crack resistance and corrosion resistance at the interface where thermomechanical stresses are most severe, thus protecting the wear protection layer from cracking and corrosion
2Strength
If hard material particles are added to increase wear resistance, then abrasion resistance is improved, but thermal expansion mismatch may cause stresses and cracking
Solution Approach 1:
The patent carefully controls the proportion of hard material particles (maximum 70 vol.%) and the proportion of matrix phase (at least 30 vol.%) to optimize the balance between wear resistance and thermal expansion compatibility. By adjusting these parameters, the wear protection layer achieves high wear resistance while maintaining sufficient ductility and toughness to accommodate thermal expansion differences without excessive stress or cracking
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
The solution significantly reduces abrasion, corrosion, and cracking, ensuring a durable and resilient friction brake body with reduced brake dust emission and improved interaction with brake pads during braking processes.
Implementation Method 1
Friction brakes for motor vehicles typically comprise a brake disc and at least one brake pad as friction brake elements. These friction brake elements, when pressed against each other, generate a frictional force that reduces speed.
Implementation Method 2
In addition to its corrosion resistance, ferritic-austenitic steel is particularly characterized by its excellent crack resistance.
Implementation Method 3
At the phase boundaries, particularly at the transition from ferrite to the more ductile austenite, cracks, such as those that occur during cooling or due to thermomechanical stresses during braking, cease to propagate due to fracture mechanics.
Implementation Method 4
The wear protection layer is applied to the base body by laser deposition welding or thermal spraying.
Implementation Method 5
The wear protection layer is applied to the base body by laser deposition welding or thermal spraying.
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a friction brake body (1) for a friction brake of a motor vehicle, in particular a brake disk (2), comprising a base body (3) made in particular from gray cast iron and comprising at least one wear resistant layer (5) formed on a friction contact surface (4) of the base body (3). According to the invention, the wear resistant layer (5) is made from ferritic-austenitic steel (6) and comprises an incorporated hard material particle (7), in particular finely distributed hard material particle (7).