Laser Hardening of Rotational Workpieces Without Surface Gaps
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for surface hardening of large rotationally symmetrical workpieces, such as rolls and cones, face limitations in achieving homogeneous hardening due to the small area of action of focused laser beams, leading to time-consuming processes and incomplete coverage of large surfaces.
Innovation Solution
A method involving a laser device that rotates the workpiece and moves along its longitudinal axis to maintain constant radiation intensity, allowing for either intermittent or continuous coverage of the surface, ensuring homogeneous hardening by adjusting the displacement or speed of the laser to prevent gaps and control energy distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a focused laser beam is used for surface hardening, then the hardness penetration depth and heating efficiency are improved, but the area of action is limited to small surfaces making large surface hardening time-consuming and non-homogeneous
Solution Approach 1:
The patent applies dynamics by making the laser device movable along the longitudinal axis of the workpiece while the workpiece rotates. This dynamic combination allows the focused laser beam to continuously scan and cover large surface areas, transforming the static limited area of action into a dynamic coverage system that can treat entire large surfaces homogeneously and efficiently
Solution Approach 2:
The patent adds dimensional movement to the laser hardening process. Instead of applying the laser beam in a single stationary position, the system introduces axial movement along the longitudinal axis combined with rotational movement, creating a two-dimensional scanning pattern that expands the effective area of action from a small circular spot to large cylindrical surfaces
2Area of stationary object
If the laser device is moved along the longitudinal axis to cover large surfaces, then the area of action is improved, but gaps may form between passes reducing hardening homogeneity
Solution Approach 1:
The patent employs feedback control where the axial position of the laser device and the rotational position of the workpiece are coordinated through a control system. This feedback mechanism ensures that the axial displacement between passes is precisely matched to the rotational coverage, preventing gaps or overlaps and maintaining homogeneous hardening across the entire surface
3Productivity
If the rotational speed is increased to reduce processing time, then the productivity is improved, but the energy input per unit area may become insufficient affecting hardening quality
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the axial displacement of the laser device based on the rotational speed of the workpiece. When rotational speed increases to improve productivity, the axial displacement between passes is相应 adjusted to maintain the correct energy input per unit area, ensuring that hardening quality is preserved while achieving higher processing speeds
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 quick, efficient, and homogeneous surface hardening of large areas, maintaining consistent energy input and reducing the formation of hardness traces, thereby extending the lifespan of tools like shape rolls and crusher cones.
Implementation Method 1
Martensitic transformation hardening by the action of concentrated high-energy laser radiation is known
Implementation Method 2
the cooling down takes place as self-quenching by the surrounding cold layers of material
Data Source
AI summary
The invention relates to a surface-hardened, rotationally symmetrical workpiece, to a hardening method and to a hardening apparatus. The proposed hardening apparatus comprises a machine frame on which two coaxially arranged rotary bearings designed to support a rotationally symmetrical workpiece are arranged, at least one rotary bearing being operatively connected to a drive device to generate rotation of the workpiece; and at lease one laser apparatus for generating focused, high-energy radiation is arranged on said rotary bearing, said laser apparatus being movable in the axial direction, and the radiation being directed toward the workpiece.