Override:Blog Titles Linkable Article Titles Not
From Joomla! Documentation
If you would like to have the titles in your blogs linkable, but them not to be linkable in the article view you need to make a layout override.
Copy components\com_content\views\article\tmpl\default.php to the html folder of your template.
Open the file.
Change lines 17-18
<a href="<?php echo $this->article->readmore_link; ?>" class="contentpagetitle<?php echo $this->escape($this->params->get('pageclass_sfx')); ?>"> <?php echo $this->escape($this->article->title); ?></a>
To
<?php echo $this->escape($this->article->title); ?>